Near the 1963 datastring, is that the abstract rampant Bohemian Lion used by the Czech proofhouses up till 1932? Also does it have a 1 on the breast of the Bohemian Lion?
No, it is the "lion/N" in use since 1931 for Nitro proof of rifled barrels. Below it is the "N in shield" mark for smoothbores.
BTW, I could identify the mark mentioned above, besides the "Krupp bullet": It is the 1940-1945 German "eagle/M" provisional proofmark for rough barrels. But this does not point to the barrels being bought in from Suhl or Zella-Mehlis: All the time this mark was in use, Weipert as well as Brno, Vienna and Ferlach were part of the Third Reich, so the 1940 German prooflaw and proofmarks were used there too.
