Mauser K98 marking I.D. help

You need to post about ten more pics to get any sort of meaningful answer. Based on the uniform dark color, the metal looks refinished to me, but that’s just a guess based on that one pic. Once the metal has been screwed with, all bets are off.

100% a Russian capture. Stock looks to have been played with stateside. Lots of people thought they would be clever and strip off the Russian shellac, pretending that it somehow made the gun more original, but it didn’t.

Nice example regardless. If the bore is good you have an excellent shooter there.