Burdars father in law made some into banjos
Yes he does. He cuts the outer section off and just uses the center. Last year I saw some of those for sale at $10 each so they definitely aren't worth much.
Personally, I'd just use them as garage art. You can hang them on the wall as-is or do your clock idea. I've got my 68 Dart's trunk lid panel on my wall. I've thought about mounting the old tail light lenses/bezels on the wall next to it. I could even wire some lights behind it. I'm going to do the same thing with my Dart's front grill/headlight surrounds. I can mount some cheap halo headlights in them too.
If you made the hubcaps into clocks, you can keep one for yourself and sell the rest. I'm sure you could get more money for a hubcap clock then the cap itself is worth.
If they are in REALLY nice shape, there's no reason why you can't put a higher price on them and try to sell them. You never know who might be looking for a really nice set. If you don't find anyone that's interested, start building clocks.