"The Man in the Frame" by Fyodor Khitruk (born Labour Day in 1917, before it was uniersally known as Labour Day) from 1966 is actually quite funny, despite its overt symbolism. It's pretty daring for its time, both in visual language and subject matter. Unfortunately, I don't know much about its history.
As the protagonist grows increasingly important, I find that he looks quite like Mussolini; just when I was thinking that the style reminded me of the Italian cartoon about "the Line". There is something decidedly kafkaesque about it as well.
Khitruk went on to make the Vinni-Pukh cartoons; the Soviet adaption of Winnie the Pooh, and is also famous for Story of a Crime and Film, Film, Film.