Don,
The inspector listing on Jan Stills's Forum
http://luger.gunboards.com/showthrea...EPTANCE-STAMPS reports c/O inspector stamps only on 1916, 1917, and 1918 Erfurts.
Görtz & Wacker's
Handbuch Deutscher Waffenstempel lists the only c/O inspector as Herr Osterode at Danzig.
--Dwight