As mentioned should be compared normal matching M95/30 StutzenKarabiner with details of butt serial number, the base stem ball marking is with H 26 could be from overhaul in 20ies, same as the K is different on safety as the imperial K on backside of bolt. Change of butt and reserial could done every Waffenmeister of small unit, no problem is easy to made, when You have dies. The old number looks still readable under angle, the 3261 is separated really from D range. Bulgarians stamped mainly on right buttstock the overhauls. Freikorps on old czechoslovak pictures are always equiped with old M95 rifles and carbines. but i dont say its confirmed, only its a possibility.