Dear Stamp Community Family
I have here some stamps from Ukraine People's Republic with overprints I was not able to identify.

The first row, the overprint is probably russian ("10 russian Rubels"), second row it looks like polnish ("Kurierske poliewa poszta", some kind of a Courier post??). I've seen some courier field post issues in the web, but their overprint was russian/ukrainian.
The last one looks like a cinderella, maybe from Government in Exile?
Thanks a lot for helping identify these stamps.
Best regards from Switzerland
André