Kuduae, when you say they all bear German proof marks, were they still proof marked "NPv" Or were Steyr given a special German mark like a stag's antler and etc., used by German proof houses?

Also, I'm thinking particularly of existing inventory on-hand from before the Anschluss, would this be over-stamped afterwards and have 2 sets of marks? I'm just wondering how it all worked in practise.