I was looking at a used featherweight on etsy. The condition listing mentioned that the wheel turns, but it was not tested for sewing. The seller "suggested" that it was a working machine. I asked does the needle go up and down when you turn the wheel? The answer was a big NO. There are a lot of non-working machines out there with some very carefully written descriptions, so be careful.
(fortunately, my lust for a featherweight has diminished, lol.)