Forgot to note the possibilities for the the initials EW might be E. Werner, E. Wagner or E. Wolf. I'd say E. Werner has the highest probability. At some point there was an E. Wahl of Zella Sankt Blasii but not sure when he hung out his shingle. E. would equate to something like Edmund, Ernst, etc. Many of the subcontractors hung out their gunamking shingle about the same time like Albert Stobbe in 1865 and Emil Eckoldt in 1876. I would expect that E.W. was at the end of his tenure as a gunsmith in 1877 as I don't recall it on later examples.

Kind Regards,

Raimey
rse