First, let me welcome you to this forum! You have a rare gun! I have one in my collection and have talked to one other person who has one. I go into detail about it in my book, but generally it is thought that these guns were made to fill a U.S. Army Air Corp contract during WWII. Supposedly they were used to shoot birds inside aircraft hangers. They may be found with the "U.S." and "Ordnance Bomb" marking. After about 11 years of research, I believe they were of limited production, and any found without the "U.S." markings were of a contract over run and sold on the civilian market. This is a personal opinion as I have found no proof of this. Is your gun "U.S." marked? In looking at your picture, you have what I describe as a First Model Utica gun, made with a slim trigger and a steel gracefully curved and tapered (to the rear) trigger guard. You can determine if your gun is original or if the barrel has been added to another gun by checking the assembly letters/numbers. They will be stamped under the barrel in front of the lug, on the inside, left top rail of the action, and under the butte plate stamped in the wood. They may not be exactly the same in all 3 places but close enough to determine that they do go together. This statement may be confusing, but after you examine several you will get the idea. Thanks for sharing your gun with us! Best wishes, Garnett