Raimey,
I have no idea about the Krupp trademark. When I was there the Firm Helmut Hoffman (?) imported a great many Remington, Colt, Smith and Wesson guns, many of which went to American Rod and Gun Clubs. They had a familial relationship with Waffen Frankonia/Jagt, and I believe many of the American guns also went through Hoffman. Hoffman was located close to Mellrichstadt so it would be convenient to go to that proofhouse.Of course other companies such as Weirauch and others in the area would go there and I don't pretend to know them all. The above map is pretty current, certainly after the "Wall came down". Before that happened, Mellrichstadt was located right at the border and would have tested many Communist guns from Suhl and possibly other areas as well. Small gunsmiths throughout the area would have also used the facility at Mellrichstadt. This is by no means a full accounting.
Mike
