Fiberglass is hard to get straight and flat, and is not very strong unless it's curved, so if you plan on making a FG case, keep that in mind. It usually looks a lot cleaner when you make it out of metal. If you want, you can make the case from metal, and make a FG enclosure to go around it to add shape and interest to it.
It's been done, use the search feature that can be found on this website, and I'm sure you'll find more than you thought possible.
BTW welcome to the forum!