Indeed it was manufactured in the Zella-Mehlis area as it wears the intertwined "ZM" proofhouse stamp. Also with the dividing line between the "172.28" and "58", I'd say the "58" is the case length. It resembles an E. Schmidt & Habermann Model 501 without a Greener safety. Zella-Mehlis was the source of these Roux(Henri Roux France?) action dreilings. Other firearms merchants offered a similar drilling and sourced the craftsmen at Zella-Mehlis. There's a current thread around somewhere on a similar longarm.
The rifled tubes had the "Star" over "H" just before the "Krupp" steel stamp and that seems to have originated at the Hänel facility and could be for Hänel but I think it is the mark of Gebhard Helmuthhauser, who was the grandfather of Helmut Schlegelmilch who was an apprentice at the Carl Gottlieb Hänel facility in the early to mid 1920s. So with that I don't think the "H.S.", who was the mechanic that fitted the tubes to the action, was for Helmut Schlegelmilch but rather for Hermann Schlegelmilch, who was at some point in the late 1930s a barrel maker. Perhaps he had a father also named Hermann Schlegelmilch and performed the work. Of course there are other possibilities for "HS" associated with Hänel such as Hans or Hugo Schmeisser of Suhl but they were more into machine guns. Also H./Hugo Schilling of Suhl might fit the bill but I don't see any Schilling forge marks. And then there's Hermann Schneider of Zella Sankt Blasii who was active from pre-WWI to pre-WWII.
There are some other interesting stamps on the scattergun tubes just ahead of the flats that looks to be a "L" over "T" with a bar thru it and some seagull type mark just below that. Just below the "Fluss Stahl Krupp" there should be some type of forge stamp and it may be below the "Imperial Eagle" & the "Crown" over "S". I would guess they were sourced elsewhere than Hänel. Let me smoke over the pics and see if I can determine anything.
Kind Regards,
Raimey
rse
