Annette,
The chain drive is pretty interesting. The light would be a definite challenge to rewire, might be better off replacing or doing away with if it proves difficult to seperate. Motor not so bad once you know how its done. Between this and the White rotary you'd have to ask myself how much you like these machines and how much time, effort , and money your willing to put into them. You'd certainly learn some new skills if you did the work yourself. Personally, I'd look for a different project closer to my interests but a few years ago I would have dove right into it.
Good Luck,
Jon