I now see that the mark overstruck by the 16.2 could be "HS" and for the person responsible for fitting the tubes to the action. I don't see an "oval" around it and it could or could not be the same person as the other "H.S.". A few choices are:
Hermann Schlegelmilch of Suhl
Hermann Schlegelmilch of Zella-Mehlis
H. Schaller of Suhl
Heinrich Scharfenbert of Zella-Mehlis
Hans Schaum of Franken & Lunenschloss(usually "F&L") of Suhl
H. Schilling of Suhl
Hugo Schilling of Suhl
Hugo and Hans Schmeisser of Suhl - probably not
Hermann Schneider, etc.
On a previous post I noted that that there was a Sauer-Schlegelmilch connection, and Schlegelmilch did source components from Sauer as well as others, but I meant to note the Sauer-Ernst Steigleder connection as Steigleder was a firearms merchant and most firearms merchants first were gunsmiths, some being master gunsmiths.
Kind Regards,
Raimey
rse