I have a Remington 1858 New Model revolver 137274. It appears to have been converted to .46 rimfire. The of the cylinder is a tight fit but it appears rough in the milling process ( not Smooth of the rear of cylinder). The barrel length is 8 ". There is also a stamping on the bottom of the barrel near the muzzle that is stamped 1915 which I have not been able to find anything about. There is also a gov't inspectors cartouche on the grip initialed JWK in a fancy script. I have attached some pics. If anyone could provide information as to approximate production date of the revolver, whether it may have seen service in the Civil War and the 1915 stamping it would be much appreciated.