started the gel coat polishing today

found that 1000grit wet and dry on my cheapie chinese sander worked well to remove the oxidation. started by wetting the glass with water mixed with laundry detergent from a spray bottle. lots of rinsing with lake water to keep it all wet and see what was being removed

then used an orbital car buffer, with a new pad, to apply a reasonably gritty car polish compound

then changed pads and used a car wax with a very fine compound

this brought up the dull gloss shine i expect to see in old but cared for fiberglass.