I have received information on my original question concerning the proof stamp on the P.22. A friend, and Walther expert in Germany, provided me with this information and I wanted to share with everyone.
"all P 22s are made and proofed in Arnsberg/Sauerland, which is the major seat of Umarex, who now own Walther/Ulm. I had a lengthy discussion with Walther because of the fact the proofing is not done in Ulm (with the traditional Ulm "antler"). But out of financial reasons, they decided against a proof by the Ulm proof house - although all P22s are made in Arnsberg, then sent to Ulm, checked through there again and sold from there. The Walther/Umarex sales management is situated in Arnsberg though."
Abwehr