As far as the maker, I'd attach a good bit of weight to Rob. Werner listed as being a parts source and early on the Werner folks were tube makers as well as most other gun making facets. Some weight could be sent toward August Richard Weissheit or Weißheit's way who was in Zella-Mehlis. I don't know if the "SS" was for Sauer or Gotthard Schillings tube factory.

Kind Regards,

Raimey
rse