This has been nagging at me for years! It's so close to Futura bold, escially in its overall proportions, but that M is not something I've ever seen in Futura. Maybe it is Futura but with an M from Granby (looking at my 1960s Berry & Johnson Encyclopedia). Have not been able to find a digital approximation, though Nobel is close (the C is not Nobel) nor is it Erbar.
This sample is a small sheet of Czech matchbook covers celebrating the Warsaw Pact. I think it's early 1960s.
Thank you for this wonderful site!