interesting! yes the 8x50R mannlicher was chambered in the lee speed rifle. we have had this many times in the lee speed forum here. the cartridge was a replacement for the 303 british on the indian market because of the military use. the british never forget the Sepoy Rebellion of 1857. the 8x50R and the lee action are still in produktion in india today.
is it sure that he use a Mannlicher M 95? this rifle was available as a sporter before WW 1 but I would not expect to find it outside of the KuK empire. or was it a Mannlicher Schoenauer Rifle in 8x56 MS?