Thank you, Raimey
This gun was examined by Igor Karklynsh, who's probably the greatest Russian sporting arms expert now. His opinion is that it is a completely original design. In 1944 the decision to resume sporitng arms production was made, and two small shops set up, one by A. Ivanov in Tula, and another by V. Scherbakov in Izhevsk.
The gun is most likely to be made by Scherbakov, and quite possibly designed by him too. Apparently, the boxlocks in the rough, or at least action blanks, were sourced from the Tula Armory, which made the Model A boxlock in many variations (including a WR-style droplock) since early XX century. As a matter of fact, the gun can be described as a development of one variation of the Model A, with the addition of the intercepting sears.
The guns were apparently meant to be gifts to the war heroes, thus the unusually high (for the pre-war USSR) level of finish and engraving.
It is known that German POWs who identified themselves as gunmakers were sent to Izhevsk, and one of those could have had a hand in building this gun.
There is still a lot to learn about this gun, and the WW2 gun production in general. Karklynsh assures that the investigation is going on.
