Kathal:
On the serial number: there looks to be a "2" on the inside of the left tube so maybe there was an additional set? Are both triggers single set? Multiple barrels sets were common with orders to Merkel. The strikers are bushed and disk set, so if it had an additional set I'd guess they weren't scattergun tubes, but who knows. A Blitz action was cheapers and easier to make with the components attached to the triggerplate, whose contour at the frame sometimes also gives it away. An Anson & Deeley(they were 2 British chaps at Westley Richards who developed the boxlock) version had the frame/receiver milled to accept the components and Merkel's top shelf model drilling was called "Specialität". Some thought that the A&D was a bit more stable than the Blitz but it all comes down to economics. I'm partial to German steel so yes I'd say the tubes would be very bright or reflective inside. So are you referring to the outside? I see that the DR had Cast Krupp steel and I'd guess that in the 1930s it had a percentage of nickel and other percentages to keep with advancements in metals but I don't recall what the Blitz Drilling tubes were: Krupp also? I'd guess the "A57" to be the serial number which is not typical for Merkel. Is the typical Gebrüder Merkel stamp on the standing breech? Are they any Merkel marks on the drilling? I see a "W" or "M" on the lower tube just below the left tube and there are some other marks like a "D" which may indicate that Merkel sourced the drilling. Also a pic of the area between the flats and the forend lug may be beneficial. Immanuel Meffert is usually given 1st credit for the alloy frames with a smaller emphasis on Christoph Funk, or that he also offered an alloy frame drilling at the time. Emil Funk was at the helm but I don't think process was perfected until the early 1930s(1933?) when the Siemens-Martin electro process(Spezial-Einsatz Stahl) was introduced. So it may just be that the outside has a coin type finish.
Usually when you have the screw at the top of the rear of the frame/receiver, it hinges an overhanging scear and with that set screw sometimes it is of the Kerner-Anson design but I don't see the lower pin which holds a spring. But Merkel made the example with some subcontractor work and it may be that their DRs are equipped with overhanging scears for safety. In considering all the Merkel klan, they were the go to guys for special orders and may have been the source to the German trade for the clamshell, mini-clamshell and pipe style(1/2 pipe in your DR case) side frame reinforcement.
Kind Regards,
Raimey
rse
