Well I haven't done the tank portion, but have had good success repainting the grill/burner area of my 500.
I used a 1200 degree paint, then baked it 500 degrees for about 1.5 hrs. The finish is nice and seems fairly durable.
But do this when you expect the better half to be out for quite some time.....the stink from the baking paint was terrible!!!!
This what my restored 500 looks like.