Well, about all I can tender for now is that the tube effort was by a W mechanic. I can't make out the other marks on the underside of the left tube. Again, the S in a Chevron is in an odd location. I for one just don't see any Suhl proofmarks. So it must have been cobbled together by a mechanic who had access to a stash of Simson components at the end of WWII. But I still contend that either Edgar Strempel, Otto Reif or both were involved.

Cheers,

Raimey
rse