It was made in Suhl & my 1st guess is that it is a E. Schmidt & Habermann Model 501, Roux-Drilling. If it doesn't have a pop-up sight for the solid projectile tube, it would be a Model 500. I don't know the patent exactly, but the E. Schmidt & Habermann Model 500 & 501 had some type patented forend latch/plunger? In fact, I'd just about lay a pretty heavy wager that E. Schmidt & Habermann either made it or sourced if for old A. Ströver of Nordhausen. I'm sure there is info on ole Ströver, but he was purely a firearms merchant that had connections to the money facet. One note that all shops had to either be a master gunsmith or have a master gunsmith on staff. I'm not sure but the widow seems to have been allowed to continue the business but for how long and when a master had to be on staff I can't say. The guild/trade looks to really have provided for their own, at least in the early years. All the grunt work was contracted to E. Schmidt & Habermann and they in turn sub-contracted the work thru economic channels. From my perspective, I really not intrigued by the peddler but the craftsman/craftsmen who made these find pieces. To my knowledge, there isn't any one such book on the makers of Suhl & Zella-Mehlis, much less those of Praha, Wein, Weipert, etc. If there is I'd like to purchase one. Too much water has passed under the bridge coupled with a lack of interest has left us with the puzzles we are now faced with. By who knows there might be a brief on many of the makers one day.
I'd also guess that Richard(Not Franz) Keller applied the engraving effort. When it comes to Austrian/Bohemian/German guns, there are zero hard and fast rules as they were constructed to the whims of the client. I'm sure it is possible for the rifled tube to be chambered in 8x57IR, but considering the drilling type, firearms merchant, lack of "IR" stamp, etc., I'd lean toward the 8x57R-360 but a chamber cast will reveal the little demon. Nordhausen is close to or in the Harz mountains where the V2 was manufactured.
The vulgar fraction, or integer, adjacent to the encircled cartridge designation(notes black powder also) has nothing to do with choke but notes a diameter of the tube 22cm ahead of the standing breech if the tube had more than 0,2mm of constriction, noted by the "Crown" over "W" which warranted at least 1 additional proof. If the "Crown" over "W" is not present, the diameter could have been measured at the business end.
Kind Regards,
Raimey
rse