Hello Mark!

I've got a question about your picture. There is the Sauer & Sohn stamp on the barrel's end.
Some days ago I bought an old double gun in .360 - 9,3x57 R, produced around 1880 at Sauer & Son and delivered by KGL. BAYER. HOFGEWEHRFABRIK v. C. STIEGELE JR. MNCHEN. This type of double gun is shown on page 8 of the J.P. Sauer & Sohn Preis-Verzeichniss of 1882.
Is yours one of this type, too?

Martin