I have sporterized large ring mauser marked "deutsche waffen und munitionsfabriken". It was sporterized by Golden State Arms, from what I looked up they did a bunch of these back in the 50s. The bolt is stamped "KM" could it be "Kaiserliche Marine"? Overall the everything looks to be in decent shape. There's some rust that I think will clean up ok but the bore looks great. I'm trying to get an idea on the age of the receiver. I'm planning on getting a boyds stock, seeing how it shoots then cleaning it up for a range gun or hunting rifle. Thanks for any info.