If it's 'fading off' rather than flaking or chipping, it was probably anodized rather than painted, which was the more standard way of doing things in the 70s and 80s. Still probably is, come to that.
When we painted our (clear) anodized mast we sanded to bare metal, mild acid wash and primed and painted with Awlgrip, a pricey 2 part polyurethane paint. It worked out very well, but as mentioned is not cheap and develops dangerous fumes requiring special protective equipment for those mixing as well as the sprayer.
You could try using the 'rolling and tipping' method, perhaps even with a single part, but as ever preparation is the key to any long lasting/good looking paint job. Keep the coating as thin as will cover.. it will last longer.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)