found some red caliper paint out from my boy racing days still debating if i'm going to use it
Paint them mate, Even if you just do them black it's got to look better than rust.
Rustoleum you already have should be up to the job.
the standard 3 in 1 stuff ?
and do you need to undercoat them first ?
Arc - what chemical treatment do you refer to? I was just thinking of rubbing mine down with wire brush, cleaning with panel wipe until they looked clean enough for paint to stick well.