I remember seeing stuff from Russia on TV in the 1970s, if not in the 1960s--usually on PBS. I distinctly remember the live action IVAN THE TERRIBLE (1944) from Segei Eisenstein.
When I was searching the list of E. European animated movies, I saw STEPAN THE SAILOR, but I dismissed it since from the title and the run time it didn't seem like the one. Now I feel stupid that I didn't give it a closer look.