You are correct. The armorer from a company called Bapty in the UK used a WWI Mauser C96 with a German rifle scope and the flash hider from a tank on the end. The original base gun no longer exists but the scope is on another Mauser and sold for millions. The base gun was used in several movies before Star Wars and after in a tv show. Mine is a combination of zinc alloy C96 replica, steel flash hider and scope mount and aluminum scope. I learned how to do chemical bluing and then weathered everything to reflect the patina of photos of the actual prop. I’m as nerdy about Star Wars as I am about GT40’s.I think the prop master for that movie got the inspiration for it from a "Broomhandle" Mauser C96. I bought one in Germany back in the early '60s. 7.63mm cartridge.