"Mauser M91 Sporter labeled C.G. Haenel Suhl 1891"
https://www.invaluable.com/auction-lot/m...15-c-9204b8dbaf

"Description: Mauser M91 Sporter labeled C.G. Haenel Suhl 1891 in 7.65mm. The barrel measures 22'' with a scope block and fixed front sight, the stock extends to 4'' on the muzzle. The butt stock has been altered with a spacer ending in a crescent steel butt plate. The detachable clip is missing. Overall fair condition with a very good base. "

looks like a winchester stock cap, 7,65 would be the 7,65x53 Belgian -Argentine

unusual in all