Try this?
I’ve got a ’78 that’s also been in the sun since new. It looked pretty bad when I bought it a couple of years ago. I was able to clean it up and make it shine by compounding and using the “Vertglass” system by Lovett Marine.The scoop, first use a buffer, mine is a Wen (yes a cheepie) 7” model 944 that’s proven to be durable and a great value for the money! I use the foam pads with 3M “Super Duty” compound to remove the oxidation form the gel coat. This stage takes quite some time, plan on a couple of days if you want to be through. You will also do quite a bit of compounding by hand as the buffer won’t reach many places on the boat-cap rails for instance. You’ll need several foam pads on hand for the boat, I used five of them.The “Vertgalss” system is a kit I bought from West Marine; it’s a boat wash, oxidation remover, sealer and sealer remover. Also included with the kit is a sealer applicator. Since I compounded the surface I didn’t use the oxidation remover, just the boat wash and sealer. The sealer is a thin-based goop that you apply with the chamois applicator. Vertgalss recommends five coats; it’s thin and easy to apply and dries quickly – 1-2 minutes in the sun. I applied it to the non-skid surfaces as well as the decks and cockpit area. When all was said and done it shined. It looked like the deck was wet after I had washed it – to get an idea-but it stayed shiny.It lasts a season, about 6 months in this part of the world) catch it before the gel coat begins to oxidize, you can touch up the thin spots, or use the sealer remover and start again with little trouble.Works for me. Boat looks good.Links:WEN Polisherhttp://www.wenproducts.com/powertools/944.htmLovett Marinehttp://www.lovettmarine.com/John.