The “Disney Dance,” what I like to call it anyway, it present in several films (e.g. “Snow White” “The Aristocats” “The Jungle Book”) and was all rotoscoped from one piece of reference film. I imagine most of the other “swaps” came from the same place, else the cells were traced over.
Remember, though, this was still done by hand. A far shake from painting over something in photoshop.
