U.M.C. Co. 12g question

Is this a dummy or a dud?

UMC Co 12g

Looks to be a dud, as dummies usually had the topwad marked - dummy

Pete, do you know which headstamp came first, “U.M.C.Cº Nº.12” or “U.M.C.CO Nº12”? The only difference is “O” in the word “Company” and the dot after Nº.

Sorry Vlad, I do not.