Some observations:
The word "bis" in German does not mean "since". It means "until" or "before". So what Herr Klemens said about the "weiteren Pra"gungen" is right. They are German proofmarks that were used before 1945.
But I can't agree with him about the big crown's being an English proofmark. I have no proof that that is wrong. I only have my pretty strong belief on the matter.
Another thing that I would like to state is that the Crown/W was not placed under every choked barrel. In the case of side by sides the Crown/W was sometimes stamped on the flat under each barrel, but sometimes it was only stamped on the flat under the more fully choked barrel.
