I started with the rpm coating. It is pretty easy to apply. First I used a Scotch-Brite pad to remove the surface rust in a few areas where it had formed. Then wiped the whole cage down with wax and grease remover, then started heating it with a heat gun and brushed on the RPM coating. It does not change the way the bar looks. I can't tell were I stopped using it.
This kind of work is hard on my back, so I'm just going to do about a half hour at a time till it's done. I estimate the whole job is going to be about 2 - 3 hours