This theme should be ripe for novelties. Some items for possible inspiration:
Candy Man
Oompa Loompas
Everlasting Gobstopper
You lose! Good day sir!
I prefer the Gene Wilder version of the film but I'm sure there are plenty of take-aways from the Johnny Depp version.
Granted, the set is probably inspired more by the chocolate than by the films, but there should still be some Wonka-related stuff you can borrow.
Edit: The top hat would make a great novelty key.