Cymbal experts......

I just got this in the mail today. The only information I got with it is that it's a 30's K Zildjian.

The Stamp is very worn. It's a heavy cymbal and I might end up using it for a bottom hihat.

Here's some closeups I took a few minutes ago. Is there any way I can for sure narrow this down to a 30's something cymbal?

Thanks,