I'm going to say that the preponderance of evidence for the tubeset knitter's initials of JW to be assigned to tube specialist Julius Wolf of Zella-Mehlis. I realize that some Germans would say that a Suhl maker would source components from the lowly Zella-Mehlis mechanics.
Below are other JW mechanics but not truly possibilities:
I did not find a J. Wagner of Suhl listed.
Julius Wahl - Zella-Mehlis - mid 1920s
Johann Gottgetreu Werner - Suhl - mid 19th Century
Julius Werner - Suhl - 1910
Josef Wilhlem - Zella-Mehlis - tube mechanic - 1930s
Julius Will - Zella - Mehlis(a small probability)
It is possible that H.A. Lindner placed an order w/ a Suhl Wolf mechanic who in turn sourced Juluis Wolf.
Like other Lindner subcontractors, Julius Wolf hung out his gunmaking shingle in 1879. Christian Wolf may have been in the mix & Adalbert Wolf was a possible successor. Anyway, Julius Wolf touted a specialist for Ausfüttern(inserts), Futterläufe(full length liners?) and Läufe für Scheibenwaffen.....
Other possible mechanics found their calling near the founding of H.A. Lindner's concern.
August Blatt(AB) of Suhl-Albrechts could reach back that far & his talent was centred around Gewehrteile und Metallwarenfabrik.
Emil Eckoldt(EE) of Suhl founded his concern in 1876 and was noted as a specialist for repairs and I believe his passed this life in 1930.
Almost forgot Albert Stobb....
And of course there are several more....
Cheers,
Raimey
rse