Mitten is a stop-motion animation film made by Roman Kachanov in 1967. You can find Kachanov's filmography here, and for a real treat, check out Mitten's Official Website (in Japanese).Gorgeous stuff, insanely cute.
Big thanks to Wojciech Jama and his site, Museum Dobranocek. It's primarily in Polish, but his vast image archive speaks for itself. A fantastic record of Slavic and European children's characters from the 1960's-70's.
He goes by many names, the elusive Colargol -- aka Jeremy, Barnaby, Beertje. If you want to see more, and I know you do, Christin from Norway has a great Colgarol site and image archive.
Illustrations by Czech artist Vojtêch Kubašta, 1914-1992. He was a master paper engineer who made exquisitely beautiful pop-up books and cards throughout the 50's, 60's, and 70's. More about Kubašta here. I so love his Noah's Ark.