I have an inherited 8mm Mauser that I started down this rabbit hole on today.
It is a double trigger "Boar Gun" built in postwar Germany for my Father in law.
The markings on the barrel are: on top 8x57
on the side of thee barrel opposite the bolt 7'9 in front of the sight and 9156 (proof mark) 48 then the proof mark again on the receiver and the scope mount blocks anything beyond that. I am not ready to dismantle it yet. I have the scope somewhere but not sure exactly where it is ATM.
There are no military markings nor any sign of them being removed. The barrel looks newer than the action.
Part of the back story is FIL Theodore D Harris was US Army occupational forces at the end of WW2. Being a competition shooter he got involved in the biergarten target shooting scene and then with the local gunsmiths who were forbidden from doing their trade. he helped jump start them by sourcing surplus US stock wood and introducing them to the US military peoples need/desire for sporting guns which they could legally make because it wasn't "rearming" Germany. This gun was a result of that. It was specifically built for MIL to go boar hunting with FIL and probably only fired a couple of times after it was built. One of the hunting/shooting magazines acknowledged his contributions in writing a obituary for him in an editorial so I assume his stories were true.
I will take real pictures later and post them later if anybody is interested. I seem to have everything down here in the workshop but a digital still camera.