Right, The more we look the more we find. The marks be left on the receiver may have been done on purpose. The action ,even when I was,a kid was extra ordinary. Original owner may have asked marks to be left for his own reason. I have seen custom Mauser's with all original marks left in place. Reason being you and I have probably seen built up scrubbed Mauser's. Question of the day is what is this thing-German or Spanish etc. Point being it would have been no big deal to totally scrub the action in all that work.The trigger guard show either a mag release or a floor plate release. Mucho custom work in that piece.