doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Looking for info on London Damascus Hammer Gun

Several years ago I bought a high quality London made 12 bore hammer gun with only this inscribed on the top rib: " Mash .10 W Wigmore Street London. 29" barrels beautiful Damascus barrels and great dimensions. The stock is gorgeous, even though it has an extension (very well done) and inlaid steel buttplate. I can't find much on the maker. any help would be most appreciated. Thanks! (The other) Gil

From an address search this conversation re: Gustavus Masu might help. Others will know more.

https://www.internetgunclub.com/forum/viewtopic.php?t=129

Can you post photos of the gun, making sure to include the barrel flat, water table, and barrel inscription?

From Grok:

This is almost certainly a gun by Gustavus Masu (also known as Gustave Masu, Masu Frères, or Masu Bros), a London gunmaker with Belgian roots operating at 10 Wigmore Street, W., in the late 19th century.
The inscription "Mash .10 W Wigmore Street London" is a very common way these appear when the engraving is worn, stylized, or partially obscured—the "u" in Masu often looks like an "h" in old script or photos, and the address matches exactly ("10 W" for 10 Wigmore Street, West). Masu guns frequently have ribs engraved along these lines (e.g., “G. Masu, 10 Wigmore Street London,” “Masu . 10 Wigmore Street London,” or similar variations with the brothers/frères name).
Background on the Maker

Gustavus Masu (born ~1824 in Belgium, died after 1876) was active in London from the mid-1860s. He had ties to Liège (a major gunmaking center) and London. His firm operated under names like Gustave Masu (1864 at 3a Wigmore St.), Masu Bros (mid-1860s), and then Gustavus Masu at 10 Wigmore Street from around 1869–1880s/early 1890s.
Masu was more of a retailer/finisher who imported or bought actions/barrels (often from Belgium) and finished/sold them under his name. His guns were generally good-quality, mid-to-upper trade pieces—not quite "best gun" level like Purdey/Boss/Holland, but well-regarded for shooting and often nicely finished.
They won recognition (e.g., honourable mention at the 1862 Great Exhibition) for quality.

Typical Features Matching Your Description

12-bore hammer guns (often sidelock, non-rebounding or rebounding hammers) were common from this maker.
29" Damascus barrels — Very typical period length for English game guns. Beautiful Damascus (twist or laminated steel) patterns were a hallmark; these were nitro-proofed later on many surviving examples for smokeless powder use (though always check proof marks and have a gunsmith inspect before shooting modern ammo).
Great dimensions and gorgeous stock — Masu guns often had nice walnut with good figure. Many had well-done stock extensions (common repairs on older guns to adjust length of pull) and steel buttplates (sometimes inlaid or engraved).
Actions were typically straightforward English-style hammer guns, sometimes with features like rotary underlevers on earlier pinfire-converted examples.

Value and Collectibility
These are desirable collector/user guns today, especially with nice Damascus barrels and original condition. Value depends heavily on:

Overall condition (barrel wall thickness, bore, action tightness, stock cracks).
Engraving quality and original finish.
Proof marks (London or Birmingham, nitro reproof if present).
Serial number (helps date it more precisely).

Comparable Masu hammer guns in good shape often sell in the low-to-mid thousands USD range at auction or through specialists, with premium for exceptional wood/Damascus. They shoot well for those who enjoy classic English guns.
Recommendations

Look for the serial number (often on the action, barrels, fore-end iron, etc.) for more precise dating.
Have a qualified gunsmith (ideally one familiar with English antiques) check it thoroughly—Damascus barrels need careful assessment for pitting, dents, and suitability for modern loads.
Resources: Books like London Gunmakers by Brown, or forums like the Internet Gun Club (IGC) and DoubleGun BBS have threads on Masu guns with photos.

If you can share photos of the full rib inscription, locks, action, proofs, or serial number, I could help narrow it down further. Nice find—these have a lot of character!

Claude disagrees a bit:

The Maker: "Mash, 10 W. Wigmore Street, London"
This almost certainly refers to George Mash, a London gunmaker who traded from Wigmore Street in the latter half of the 19th century. Wigmore Street was a respectable but not quite "best" London address — not Bond Street or St. James's, but a legitimate West End trade location catering to a solid middle-to-upper-middle-class clientele.
George Mash is documented in London trade directories of the 1860s–1880s period. He was a retail gunmaker and agent rather than a manufacturing "maker" in the strictest sense — meaning he likely had guns built to his order by Birmingham or London trade manufacturers and retailed them under his own name, which was absolutely standard practice. The "10 Wigmore Street" address helps narrow the date; London gunmakers moved around, and pinning an address to directory records can give you a manufacturing window within a decade or so.
The abbreviated "Mash" on the rib (rather than a full name) is consistent with rib engraving conventions where space was limited on a straight, narrow top rib.

The Gun Itself
29" barrels on a hammer gun of this era are a very typical and practical length — neither the longer wildfowling barrels nor a shortened game gun. This is a standard all-round game gun length.
Damascus barrels described as "beautiful" suggests a quality iron/steel weld pattern — likely a multi-iron twist or fine Damascus rather than common twist. On a London-retailed gun of any pretension, the barrel quality would have been a selling point, and good Damascus from this era is genuinely attractive, often with a fine figured pattern when properly browned or re-browned.
"Great dimensions" — I'd love to know the specifics. Length of pull, drop at comb and heel, cast? These details would tell you a lot about whether this was a bespoke or semi-bespoke piece vs. a standard off-the-shelf stocked gun.

The Stock
A well-executed stock extension is not a red flag on a gun of this age — it's actually rather common and speaks to the gun having been used and valued enough to be properly fitted to a subsequent owner. A clumsily done extension devalues and weakens; a well-done one, properly fitted and finished, is essentially neutral. The inlaid steel buttplate is a nice period detail and more durable than a horn plate.

Dating
Without proof marks or action serial numbers, a Wigmore Street Mash hammer gun with Damascus barrels most likely dates to circa 1865–1885, with the probability highest in the 1870s. By the late 1880s, hammerless actions were becoming fashionable among London retailers, and hammer guns were increasingly the economy or conservative-buyer option.

What Would Help Narrow Things Down

Proof marks on the flats — London or Birmingham, and the specific mark (view + definitive, and any reproof marks)
Serial number on the action bar or other parts
Lock style — bar-action or back-action? Rebounding locks?
Choke or cylinder boring stamped on the flats
Action maker's name anywhere — sometimes the trade maker is stamped on the water table

Do you have any of those details? Particularly the proof marks — those are often the most reliable dating tool on a gun like this.

Perplexity goes along with Grok:

What you likely have is a Gustavus Masu London-made 12-bore hammer gun, and the rib address “10 W Wigmore Street London” matches period listings for Gustavus Masu / Masu Brothers at Wigmore Street in the late 1860s–1870s. Contemporary references also show that a Masu gun with that address has been recognized by collectors, including a 12-bore example described as circa 1870.
Maker and dating

The “Mash” inscription is probably a misread or worn version of Masu; the surname is documented in London gun trade references at Wigmore Street, including “10 Wigmore Street, W.” and earlier “3a Wigmore Street.”
That points to a gun from roughly the late 1860s to early 1870s, before the move to later addresses.
What the gun style suggests

A London 12-bore hammer gun with 29-inch Damascus barrels fits the style of a high-quality black-powder-era sporting gun. Damascus barrels were common on finer British guns of that period, and surviving examples are often valued for their pattern-welded appearance and craftsmanship.
The “great dimensions” you mention matter a lot: if the gun still handles well, that can make it very desirable to a collector or vintage-gun shooter.
Stock and furniture

A beautifully figured stock with a professionally done extension and an inlaid steel buttplate suggests careful restoration rather than rough alteration. On an old London gun, a good extension is not automatically a flaw if it’s well executed and the rest of the gun remains original and tight.
Those details can preserve usability while still keeping much of the gun’s visual appeal.
Shooting value and caution

Damascus-barreled shotguns can be safe to shoot if they are sound and properly inspected, but chamber length, barrel wall condition, proof status, and load pressure matter a lot. British Damascus guns are often associated with black powder or low-pressure ammunition, and a vintage gun should not be assumed safe with modern high-pressure loads.
A competent gunsmith should check the bores, proof marks, chamber length, and action tightness before any shooting.
What I’d do next

The most useful next step is to look for:

maker’s name on the locks or under the rib.

serial number on barrels, action, fore-end iron, and trigger guard.

proof marks on the barrel flats.

any patent or address wording beyond the top rib.

If you share photos of the rib, lock plates, barrel flats, and proof marks, I can usually narrow the maker and date range much more precisely.

Chat GPT is also on the Masu bus:

What you likely have is a late-19th century London-retail Belgian-built sporting hammer gun sold by Gustave Masu / “Masu Bros.” of Wigmore Street. The rib inscription you’re reading as:

“Mash .10 W Wigmore Street London”

is almost certainly:

“Masu, 10 W. Wigmore Street, London”

The firm operated from 10 Wigmore Street from about 1869/1870 through the 1890s.

A few important things about these guns:

Masu was associated with Liège, Belgium gunmaking, while retailing through a fashionable London address.
Many were very well-made guns, often with excellent Damascus barrels and attractive stocking.
They are not generally considered “best London guns” in the Purdey/Boss/Holland sense, but good examples can be superb shooters and very elegant sporting guns.
The Belgian connection is not a negative in itself. Liège produced huge numbers of fine sporting arms in that era.

Your description actually sounds unusually appealing:

29" Damascus barrels
“great dimensions”
gorgeous stock
steel buttplate
well-done extension

Those are all signs someone cared about the gun over its life.

The key to understanding value and quality is in the details you haven’t mentioned yet:

1. Proof marks

Remove the barrels and photograph:

barrel flats
water table/action flats
underside of barrels

These marks will tell whether:

it has Belgian proofs,
London/Birmingham reproofs,
chamber length,
black powder vs nitro proof,
approximate era.

That’s the single most important clue.

2. Action type

Is it:

Jones underlever?
top lever?
rebounding locks?
back-action or bar-action locks?

That helps narrow date and quality level.

3. Damascus pattern

Fine “stub,” “crolle,” or “Bernard” Damascus can indicate a higher-grade gun. The fact that you called the barrels “beautiful” is promising.

4. Bore and wall condition

Condition matters enormously:

dents?
pits?
wall thickness?
on face?
looseness?
original barrel length?

A gorgeous old hammer gun can go from a wall-hanger to a highly desirable field gun depending on those points.

Dating estimate

Based on the address “10 W. Wigmore Street,” I’d estimate roughly:

circa 1870–1890

If it has exposed hammers and Damascus barrels, that fits perfectly with the period.

Collectability/value

Masu guns are somewhat under-the-radar today, which means:

they don’t bring Purdey money,
but knowledgeable hammer-gun enthusiasts often appreciate them.

A clean, mechanically sound, attractive Masu hammer gun with good dimensions and strong Damascus can absolutely have meaningful collector and shooter interest.

If you want, upload photos of:

the rib inscription,
full gun both sides,
action,
proof marks,
barrel flats,
Damascus closeups,

and I can probably tell you:

approximate date,
Belgian vs English proof history,
likely original quality level,
whether it was a higher-grade gun,
and a realistic current-market value range.

A good illustration of the power of AI, eh?