Interesting that I've seen 2 similar puzzles within a week. If it has an "Eagle Nitro" stamp on each scattergun tube, then that is a post-1912 mark. The "Crown" over "N" 2,4g G.B.P./St. m.G. is a July 23rd, 1893-1912 smokeless proof applied to a tube that experienced proof with a solid projectile. 2.4 grams of Gewehr Blattchen Pulver(smokeless leaf powder) with a Stahl Mantel Geschoss(steel jacket solid projectile). The mm stamp replaced the pre-rifling bore diameter stamp circa 1910. Although a possibility, I don't think it is a pre-1912 proofed example if it has the "Eagle Nitro" stamp on the scattergun tubes. So I would guess the preliminary proof was prior to 1912 and the longarm was completed and experienced final proof post 1912. I'd say your drilling is typical of the abilities of the Suhl craftsmen and that is why Suhl was so heavily sourced.
Here's a Funk double rifle drilling similar example:
Kind Regards,
Raimey
rse
