I won this rifle at auction recently for a steal. It's all matching but the bolt, which is scrubbed. I can tell it's probably a Weimar rebuild from the 4 digit serial number on the front band and the stock being the wrong style than what was used in 1918. Any idea why this bolt was scrubbed? It has a Polish handguard which I assume was put on stateside. It's missing the rear sight slider button. I can find a complete Polish rear sight, but would prefer just the button if I can. I assume the Polish one would work though, right? It's also missing the rear band screw. I assume that is unobtanium, but maybe I could find one at the hardware store that can work?