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.
Like he said.
My 60' stick was well worn - no anodizing left at all and a lot of oxidation. I stripped it to the bare tube, sanded it with discs used by auto shops - they are a resinated plastic mesh and work absolutely great in this circumstance. You use them with a small angle grinder. Some use of another autobody sanding disc - a disc with sandpaper laid around it in an overlapping pattern like shingles - also used in an angle grinder.
Some hand sanding was required in nooks & crannies then the painter went over the whole thing with red Scotchbrite pads, wiped it with sovent and then sprayed Awlgrip primer. When that was done the topcoat Awlgrip was sprayed.
Stripping the hardware from an old mast was brutal - I broke a couple of deadblow hammers. An impact driver is essential. It took about a week to clean it off except for two cleats - they weren't coming off so they became integral parts of the mast.
Doing the prep myself and just having a pro spray it kept my cost to about a grand - for a 60' mainmast, a 15' boom, a 28' mizzen and an 8' boom. About a third of that was just for the paint - 2-part poly's are worse than bottom paint.
I stupidly forgot about my spinnaker pole and jockey pole so they are still worn anodizing.