Also, Droop was redesigned from a Frackle called P.J. Dripsnout from "The Great Santa Claus Switch". He had some other name when they sound off (in the elves' workshop) but I couldn't make it out.
Jog, good list. Those are all the important ones. There were a few cameos too:
#3 Joel Grey: in "Comedy Tonight"
#14 Sandy Duncan: one of the singers in the closing number, "Try to Remember"
#34 George Burns: dances with Zelda Rose in At the Dance
#36 Bernadette Peters: one of the singers in "Just One Person"
#56 Loretta Lynn: appears in opening credits
#60 James Coco: plays in the band in closing number, "Short People"
#65 Spike Milligan: he appears throughout, I believe as a Mexican
#86 Liza Minnelli: nightclub patron in "Copacabana"
#106 Jean-Pierre Rampal: one of the conga dancing patients in Vet's Hospital (I'm pretty sure; I think he has a bandage on his nose)
That's all I know.
David "Gorgon Heap" Ebersole