The "pick and sole" (actually a miner's trough) is simply the crest of Suhl city. It was used to make clear the gun was made in the more prestigious Suhl, not in that "inferior" competing gunmaking town Zella-Mehlis nearby. Since 1940 it is part of the proofmarks, denoting proof by the Suhl proofhouse. I don't believe it points to any specific maker! The words "Made in Prussia" found on many Suhl guns exported to the USA served the same purpose, as Zella and Mehlis were not in Prussia, but in Saxe-Coburg-Gotha.