The Russian Mosin Nagant Forum

I seriously doubt there is a paper trail. If there was, it would been widely known in the collecting world.

Sometimes military rifles have marks from the capturing nation. Sometimes they dont. Without marks or stamps you really cant tell.

Most veterans who brought home a trophy weapon did two things when they got home. Tossed all the paperwork in the trash, and then either stuck the weapon in a closet, or hacked it up into a hunting rifle. So far as I know there is no way to search anything from a serial number on a captured weapon.