Well, it does look short...

Definitely shorter than a std. M98, and shorter than a SR Mexican 98. It looks about the right length for a Kurz, but the bolt handle does not look right to me for an Oberndorf commercial Kurz, and neither does the trigger guard or the striker nut.

Perhaps it is a military action that somebody shortened by cutting & welding. Or maybe the bolt & guard were replaced.

There should be serial numbers and proof marks that would tell a knowledgeable collector if the receiver is an Original Oberndorf Kurz.