Jim, the "Y31V" is an assembly number. It should be on the bottom of the barrel in front of the lug, on the inside top left side of the frame, and if the stock has not been shortened, stamped into the wood under the butt plate. If all 3 numbers match (more or less) then that is a good indication the gun left the factory with that barrel and stock. Your gun is what I call a "2nd Model Utica". This means it has a slim profile trigger with an alloy trigger guard. The "1st Model Uticas" had a gracefully shaped steel shotgun style trigger guard tapering to the rear. Also, another feature your gun has is the uncommon factory drilled and tapped for a side mount scope base. The barrel writing is normally on the left side of the barrel, but when fitted for a scope at the factory, they moved the writing to the top center of the barrel to avoid drilling holes into the writing. I do not believe the M/S style forearm is a factory original. Nor is the checkering. Notice that it is more of a square than a diamond pattern. However, the checkering on the stock is of a diamond pattern. If you can send a full picture of the stock along with the length of pull I can hopefully determine if the stock is original to the gun. Also, a picture of the inside and outside of the butt plate would help. The frame has been reblued and turned red/purple due to the nickel content in the metal. All in all, you did great on the price! The readers of my book have shared with me that for an inexpensive gun, they are very accurate, but have a terrible trigger pull. Your gun would have been made between 1936 and 1946. After that the company moved to Chicopee Falls. I hope this info helps.
