The wheels may be aluminum. Either way, you could prolly strip them down and polish them. I would spray a clear sealer on them. Oh and polishing them is a real pain, it ain't easy. If it was, more peeps would be doing it. Just get them chrome dipped or powder coated. It would be better in the long run.
http://eastcoastpowdercoating.com/
http://chromeplating.com/
Good Luck.