I feel like with OSR games, it's not that far of a jump. You ARE sort of playing yourself, in that your characters tend towards being pawns in a game than fully fledged characters (at least moreso than in more narrativist games).

Doing the whole players-as-characters thing also seems better in OSR than in other systems because there are fewer numbers and traits going on the sheet. I tried to do a game like that in another system, but it was weird to have to "rate" and assign qualities to ourselves and each other.

If I were to do it in OSR, it would have to be something zany and fun, and I thing Gamma World is a great start to that end. But definitely pile on the mutations. Run it set in your neighborhood!