Those other two stamps make sense with them being outside the barrel nut cuz the rifle would need to be headspaced in order to be proof marked. But the straightening marks have a chance of being hidden since its done before the barrel is fitted to the action but they still dont know where the marks will end up since they dont know for sure how the headspace will end up.

Hopefully sharpshooter can chime in and lay it all out. Every action is stamped as well w codes that lay out the caliber and configuration of the rifle from what ive read on this forum.

Brian