This is a rough but rather curious M1900: Gunbroker

The seller writes; "Up for auction is a Steyr Mannlicher Schoenauer Model 1900 chambered in 6.5X54 caliber. The 22" barrel has a bore is bright, shiny and clean with strong rifling. The stock looks original, with minor handling marks as seen in the pics. The serial number is 95XX, I have obscured the serial number digits to protect the buyer.I can not find any history on this gun so any information that I could add to this listing would be appreciated."

It has the early, outboard mounted, magazine release and is in a stock that clearly is not original as it does not even fit:

Early magazine release

Note the Mauser looking 'thumb notch' in stock with no corresponding dip on MS receiver

Vast gaps between wood and metal

Filler in front of trigger guard