Now the was an Erich Kelber who was active in the 1930s with automated tube machinery, but I don't seen any other Kelber type stamps and thus rule him out. It is a script "E.K."(looks to be a poor stamping effort) and the Kelber's did for the most part use script, but I still hold to Emil Klett until a preponderance of evidence proves otherwise.


Kind Regards,

Raimey
rse