Re: Anyone know the name of the lost ring in donut film?
I remembered this film as soon as you mentioned the ring, I probably haven't thought about this since the '70s. This was an easy one:
"The Donuts" (1963)
It was posted on Youtube a few years ago, but it appears to have been removed due to a copyright claim. Not a Festival title to my knowledge, but probably one of those scratchy 16mm films that got pulled out at school when it rained during recess. :)