Repair Help!

On my first Sunfish's hull, I used automobile-type filler...

My question is this, does this hull need a professional re-gel-coating, or can I apply Marine-Tex (or something else) to bring the condition up to "very smooth"? Hopefully, a photo of the very worst part View attachment 15500 will appear below:
Unless this were a newer and particularly valuable Vanguard-era or more recent boat, I would be reluctant to go pro too quickly. As with any restoration it is way too easy to spend far more than the finished project will ever be worth. If you have a competent friend with the paint spraying equipment and experience, that could be different, however. I that case I would sand pretty much to the glass, and thin some gelcoat quite a bit for spraying.

I would not use MarineTex as a large-area fairing material. It is terrific for hard-as-nails repairs of chips and cracks. For something that you can thicken or thin, use to fill gouges, and sand to near-perfection the West System mixed with one of West System's fairing compounds (comes in different grades for a range of densities, in white cylindrical containers, available at hobby shops or online). Sand, apply sparingly, let dry, and sand.

Again it depends on what you are doing with the boat, but for recreation or club racing I would sand it best I could, maybe fill and sand the worst of the gouges, and then look at coating exposed glass areas that need the UV protection. UV protection would be my objective more than cosmetics. If there were just some small exposed areas I would maybe just use a bit of UV protective spray paint and sand. If you have the friend with a spayer, gelcoat could be an option, but it should be thinned.

Now this is over the top whinsical, and for sure 'decorative' rather than fast, but I have done it and it looks cooler than all get-out (it looks even better when dealing with top-side deck gouges). There may have been beer involved in this project. Pick up a can of Rustoleum 'hammered' spray paint, like 'hammered bronze' or 'hammered nickle' and spray the gouges that color,, filling the gouges and maybe overspraying. When it dries, sand the area thoroughly. The overspray will sand off and the hull will be nice and white but the gouges will look like there is some kind of sparkling metallic material under the gelcoat. It looks better than it sounds.