As a side note, & just a conversation piece as I have yet to see the mark, but there was a Vorrat/Vorratszzeichen/On-Hand/On Dealer's Shelves mark that was the Double Headed Imperial Eagle w/ a >>V<< on the Breastplate. Even longarms that were close to completion on the day the law became effective had the option of the Vorrat stamp. But within a year, the weapon had to be submitted to the Proof House for Inspection. Now what that was, was probably anything but proof....
Hochachtungsvoll,
Raimey
rse