Help with possible origin

[yuanzhumin]

I also thought of Tibet and even Mandchuria, whose writing is very similar for the neophyte like me. But after careful thinking, I abandonned the tibetan option. It's very subjective, I have to say. May be I'm completely wrong.
But the fact that there is latin or even cyrillic letters on the other side of the drum could corroborate the mongolian option, in the 20's/30's.