Questions on Proof Dates and metal finish

[offhand35]

I have recently acquired an H. Scherping 16ga sxs, and have some questions. Was there a date/year that the proof date was first required to be marked on shotgun barrels? This Scherping is NITRO proofed, but has no proof date marked. Knowing when proof date marks were required would help bracket the mfr. date for the this gun.
Also, this gun was apparently stored for quite some time in a foam lined case and the barrel finish is badly mottled. My gunsmith asked what process was typically used to blue German guns. He seem interested in refinishing them as correctly as possible, even though I had not asked (yet).
I can post some photos, but they are from the seller, don't really show the barrel finish.

[mike ford]

offhand35,
I was unable to magnify the images( even with help) enough to be able to read the proof marks. In general, I'm not sure whether the dating of proof was a matter of law or of procedure of the proof house. The dating of proof in the Suhl proof house started around 1922, whereas the Zella Mehlis proof house started much earlier ( I have one from 1909). My guess is the gun was likely proofed between 1912 and 1922 in the Suhl proof house. Keep in mind, this is a guess. A gun of this age would have a 65mm chamber( 2 1/2- 2 9/16") rather than todays standard 70mm ( 2 3/4") one. The barrels would no doubt have been blued by the " slow rust blue" process, whereas the smaller blued parts most likely were blued by the hot salts ( dip) process. The frame, lockplates, etc. seem to have been case hardened. The slow rust process would have been used to prevent damage to the soft solder joints joining the ribs to the barrels. Sorry I couldn't be more helpful. Maybe someone else can get a look at the proof marks.
Mike

[offhand35]

Thank you Mike. I was guessing proof to have been 1912 or later, Even up to 1922 is better than up to mid 1930's when Scherping closed down. Yes they are 2 1/2" chambers. My CSMC 16ga chamber gauge does not come close to the 2 9/16 mark, but have no problem putting 2 1/2" brass shells in. The frame and locks actually appear to have been left in the white but have some tarnish now that I am trying to gently clean off. i tried lacquer thinner on cotton, but may try some 0000 steel wool with the lacquer thinner next. Just to clean, not polish bright.
I will ask my gunsmith what process he uses for reblue. I would not want the flats on the bbls blued.

[mike ford]

offhand35,
You are correct that the flats should be bright; so should the sides of the locking lugs, the extractor and rear face of the barrels, and the muzzle. In rust bluing, some of the solution often winds up on these areas; but after the process is finished, these areas are easily cleaned up with worn 320 grit abrasive, backed by a file.
Mike