May be after a Red Herring here. Difficult to track Gustahlwerke Witten as another concern either had or was using the term Excelsior. But Gustahlwerke Witten was active in 1937 to 1941 and seems they had or were developing a Edelstahl or stainless steel.


Ruhrstahl - Witten





Ruhrstahl - Stahlguss

Kind Regards,

Raimey
rse