I recently found this gun at a local gun store and I was unfamiliar with the makers name and know little of shotguns made in the UK. I think it's a very unique gun being it has 28" fluid steel barrels with .045 constriction in the left and .048 constriction in the right. Originally proofed for 3 1/4" shells and reproofed for 3 1/2" shells. A straight grip stock with modern dimensions. Light for a ten at just over 8 1/2 pounds. I can't imagine there are too many like it. I came into contact with a previous owner in the UK quite by chance. He gave me some history of the gun which I find rather fascinating. Anyone else have a fluid steel Mortimore & Son? All thoughts on the gun are welcome, there doesn't seem to be much information out there about them..

This gun was made for a Mr F.W. Smith and sold on the 1st August 1929. It had 28" steel barrels with 3-1/4" chambers choked Full & Full. It weighed 8lbs 9oz and it was stipulated in the original order that there was to be no checkering on stock or forend. The original stock dimensions were: Length to centre 14 5/8". Drop at comb 1-1/8" Drop at heel 2-1/8". In the intervening years the chambers were lengthened and the gun proofed for 3-1/2"(89mm) cartridges. The stock and forend were also checkered at some time.

How do I know all this? I used to own this gun and the info above came from Dickson's when they were still in the Frederick Street shop. Sam Wilcox looked it up for me and I've just read all that info off Gary MacPherson's business card that I wrote everything down on.
I had the Silvers pattern rubber recoil pad fitted by former Churchill Gunmakers stocker Jeff Tyrrell who lived a couple of doors from my Mum in Sutton Coldfield.

I often speculated on why the gun had been ordered with that specification. Across the Firth of Forth there are large numbers of greylag and pink foot geese in Fife and there also numbers to be found east of Edinburgh. Both these areas have rich arable farming and the geese flight into the fields to feed. It's my belief that the gun was ordered with 28" barrels to make it handier to use when hiding in a ditch or hedge alongside the fields. Omitting the checkering would, no doubt, have made the gun easier to clean because the rich soil can soon clog up checkering. The choice of a 3-1/4" 10ga would give quite an improvement on 12 magnum performance. Whilst not as powerful as an 8ga, with it's 28" barrels it would have been a lot handier and with its 1-3/4oz shot load it wouldn't have been far behind the bigger gun in performance.

https://photos.app.goo.gl/CfUs9icEUD1vajRt8