Even if this gun was originally a byf 42 straight up military version there is a LOT to account for on how it was faked. Much for instance than just a swapped out center toggle link and police sear safety added along with police acceptance stamp. We also have to account for the frame which either had the suffix added or is a donner byf 41 y block re-numbered to match, reblued and then I suppose distressed to appear not reblued…. All getting very weird at this last degree maybe done by ancient aliens would be more plausible