Very nice set, Rarenum! Im jealous of the 1767 CM... the only one im missing!
Just to clarify, CM did not refer to Suzun until the coins of Nicholas I.
The coins from Suzun, also known Kolyvan, had the mintmark KM on 5 kopecks, dengas, and polushkas of Catherine II, as well as the Siberian Series 10, 5, 2, 1, dengas and polushkas.
Your coins here, with mintmark CM, are from the Sestroretsk Mint, which was in St.Petersburg! They are not easy to find, to be sure!