I have the same problem with the plastic pieces on my car. If you fabricate one, what are your plans? You think it would be easy to make something similar using fiberglass?
Don't think I'm going to fiberglass this job.
I have my own (homemade) vacuum forming machine that works quite well. My wife asks me to form certain objects so she can make concrete molds of them, decorate and gives them out as gifts/etc/etc. BUT, I will be using it forming my own center console tray's/speaker baffles/etc with it once I get to that part of the build.
That being said, I buy plastic sheets from a local supplier here in town that I use with that machine and was thinking I could simply use the same PVC plastic material (comes in multiple thicknesses) and form my own edging by clamping it in place on the inside of the door cart location and molding it around that edge with a heat gun. Cut to specific size to mount and paint.
Some of those plastics have the same textured look to them as well but that's something I wont be worrying about myself. I think it should be fairly easy. I've help mold custom tail light lenses in the past using the same process.