Holiday From Rules
TCM recently ran "One Got Fat" in the wee hours and I taped it because my kids love your version. After it, they ran a short called "Holiday From Rules" from the mid to late 50s (based on hair & clothing; I didn't notice a copyright date).
Four kids complain about living with rules and they're sent to an island of cardboard stand-up mountains complete with animated shark-infested waters. It descends into Lord of the Rings with fighting over games, shells, and food. One boy breaks his arm and, even though he broke it fetching a coconut, he doesn't get any of the food and sits there watching the others sink into their shares like lions.
There are a lot of pauses and dead air for riff space and the kids are abysmal and perfect to riff on. I hope you check it out: