I purchased a 1987 Hobie 17 late last summer. Overall the boat is in good shape but the hulls need to good refinishing. There are several spots with gouges/scratches as well as gel coat crackes (deck and gudgeons attach to the transom). I was considering using the West System to fill the gouges and scratches and perhaps NewGlass on the hulls.
If you like the color consider sanding thru the grits, and polishing the hulls with machines. There is a thick coat of gelcoat to work with. 120-600 grits should do it. There are many polishing compounds and treatments for plastics which give quite a luster. If you do that fill the scratches with polyester of a matching color. Paint adds weight and can scratch off. West epoxy is good for structural repairs on the inside, but is ugly, has no uv protection, and must be painted over.