Yay, thank you for this class Professor Dosier.
I've said it before, I'll say it again, Jerry is the "Man".
Oh, and I'd also like to point out something that made my draconic roommate furrow his brows. You state the first time Jerry performed Uncle D was in the TMS episode gueststarring Twiggy. Dunno if due to the production dates that would be true, but that was Episode 21 of Season 1... And chronologically, at least by episode's sakes, the first instance of Jerry performing Uncle Deadly was in the TMS episode featuring Vincent Price, Episode 19, a full two episodes prior to his introduction/origin story in the Twiggy episode.
BTW: Do you think Uncle D would be the defacto choice for Muppet boss character to confront if a remake of Muppet Racemania with four tracks based on the2011 film were to be produced?
They'd have to drop the Fraggle Rock tracks though, maybe replace them with more theater-based levels, that sort of thing.