This is one of the front wheels. It looks as though there is a lot of rust creeping through, but as you'll see below there's lot of good chrome and the rust colour is a protective wax.
Before
After
The before and after pictures really show what can be done with some time and effort with a Dremel and a soft wire brush attachment. The inside of the wheels had a lot of much harder to get off dirt but they are coming up quite well too.