The last of my cels from the Jello ads, first up is the Alice that I got along with the Gryphon. The white headband seems to be a trademark feature of cels from the Jello ads. The effects cel of the water is interesting, and certainly not from the two video clips I have.
Next is another Art Corner setup, this time with Alice and the Caterpillar as a butterfly. This originally had another cel as well, Toughy from Lady and the Tramp (go figure). Again, the two clips I have do not feature the Caterpillar, so there must be more Jello ads out there somewhere.
I do not have a reliable date on the ads. The video collection I have says 1956, but I have no other evidence of that date. The campaign materials I have from the original release do not mention Jello anywhere, in fact one of the larger campaigns for the original release was with a competitor, Royal Desserts.