"...not sure if 8mm Mauser or not..." Slug the barrel and do a chamber cast. Like Patrick says, M95's came in several 8mm cartridges. 8×50mmR Mannlicher(.321" bullet), 8×56mmR(.329" bullet) and 8×57mm I/JS(.323" bullet). Other than the Mauser JS, none of 'em are exactly common. The 'Mannlicher' part matters too. The Frenchicon had an 8×50mmR as well.
$500 is kind of steep though. Look on the assorted auction sites. There are several on Gunbroker for less.
"...in need of a stock, safety knob..." That'd settle it for me. The 'mum' increases value, but not with an aftermarket stock. If you can find one. Rummage around here. Nambu World