You can remove the pitted rust on the chrome by sanding it. You will work from 400-grade sandpaper through 00000-grade steel wool. When you’re finished, apply two coats of lacquer making sure that you wear a breathing mask and eye protection while applying the lacquer.
Do be careful, as sanding the chrome may leave scratches on it. The best method is to prevent the chrome from becoming pitted by using WD-40 on rusty spots or using aluminum foil to buff the chrome.