You could be courageous and refinish with Gel Coat.
My son turned a corner a little too tight and damaged a fender. Fortunately it was without the boat on so the damage turned out to be minor depending upon your point of view. It was a crack in the fiberglass which I mended by dumping some thin CA glue it to the crack. I was lucky in the fact that no real pieces were missing. Then I sanded the top. I filled the very minor divot with Gel Coat Paste. I ended up trying to thin the Gel Paste so that I could spray. It matches pretty good color wise but I got a rather dull (almost orange peel) effect. I've been letting it set so that the Gel would fully cure and then I'm going to try 1500 sand paper, followed by compound, etc - you know the drill; actually that is an excuse as I'm too busy using the boat this time of year. We'll see how it turns out but that is a project for later. If cannot get the Gel to shine I decided that it will be an off season project to just go ahead and redo with the proper Gel (non-paste) for spraying.