Some of you may have seen my other thread - I am helping a friend of the family sell a collection for a relative that had to go into a home. He has this rifle - it is clearly a Mauser action and has been engraved and a double set trigger added. I can find nothing indicating caliber or manufacturer. The only clue to the origin is a single German proof mark on the receiver. Can anyone help identify this? Proof mark is shown in photo 2037.
Pictures here
https://drive.google.com/open?id=0B2VPnSef8jw2X19YcVNGX2F0bmM
Pictures here
https://drive.google.com/open?id=0B2VPnSef8jw2X19YcVNGX2F0bmM