Hi Matt, if you do a search, you will find some good info on removing the trim, and fibreglassing the belly band. I did it to a '76 Trillium
1300, and it looks fantastic. Plus, it was not hard to do at all, and if you are fine with doing glass work, you could handle it.
After grinding out the joint to accept glass cloth, glass matt, and then glass reinforced filler, I did remove many of the backing plates, as they were near the surface, and easy to get out. Some of the ones embedded well, and that would be at least 1/8" below the surface, I left in place. This post describes what I did.
1976 Trillium 1300 Remodel - For Caitlin
Boy, I really need to update that thread.