Hi,
I am a newer owner as well (IP 35). I am currently in the middle of refurbishing my gelcoat right now. I sanded the entire deck and cabin with 800 grit wet sandpaper to get rid of the oxidized gelcoat. Mine was all chalky with white streaks down the cabin sides. Now it is all an even color, but dull. Just finished that part yesterday.
My plan is now to polish. First with a heavy cut, I'm using McGuire's oxidation remover (not enough to actually remove the amount of oxidation I had in a timely manner). Then polish again with a lower cut. Hopefully after that, she'll be shiny enough for wax.
I'll keep you up to date when I'm done. Maybe I'll include some photos.