Malvina's daughter here. The "Money's dandy" verse was indeed added later, when the song was used in a beach movie and the producers thought the original bridge was too risqué:

They said "don't play with fire,
Once burned twice shy."
But now I've played with fire
And all I want to do is fry.

Movie standards have changed a lot since 1958. Of course, if it had had the original verse it wouldn't have ended up in the Girl Scout song book. Judy Fjell changes the money verse from "Money's dandy and we like to use it" to "Money's dandy if you like to use it" and that's one of the few changes people have made that I think improves on the original.