Serbian Mausers M1899, M1899/07 & M1908
Manuf by Steyr
M1899 Mausers were contracted for by Serbia with both DWM & Steyr. These rifles are small ring Mausers similar to the M1895 Chilean Mauser, but with a thumb cut in the left side rail. The M1908 was also produced as a full stocked carbine with turned down bolt. The model is stamped under a Serbian crest on the top of the receiver over the chamber.
Theses rifles & carbines were origonally in 7x57mm but most have been converted to 8x57mm Mauser caliber.
Roughly translated to "Oesterreich Waffenfabrique Gesellschaft Steyr", found on the left side rail (in Cyrillic) on Steyr made M1899's, etc.
Web Link to a good short history of Yugoslavia and its arms: Serb Weapons