I tried that once. It would have to be split above the body line and filled in. Not impossible, but not exactly easy. There was a couple other things, but that was the major stopping point. I do know VFN will make fenders if you have a good factory fender to mold off of, they just don't exactly do it for free! Also, a good fiberglass person, say someone who repairs fiberglass boats might be a good one to ask about making some off of your good fenders too.
We used to have a guy here that did custom showers in highend homes and one the side he would lay his paper ( i don't know the propper name for this film he put on) on your good frontend or fenders, doors etc., and make the mold. When he then made the parts from this mold, they were exactly what your car had to begin with except fiberglass instead of metal. He even did a pair of dented fenders and dented doors
for a friend of mine who strictly street raced for bucks. Want to talk about deception at midnight !!!
Just a couple ideas for ways to get your Fiberglass parts. I can't wait til you have this new car done!! It will be very cool.