Sea Dog, OP has a pop-up camper, not a TT.
Most pop-up campers I have seen, especially from the 2000-2005 era have "plastic" foam roofs or sheet aluminum.
In the plastic foam roofs, a sandwich of Royalex, polyethylene, or similar skin is glued/molded to a foam core (both sides of the foam core are skinned, sometimes with different materials on each side). Actual fiberglass was seldom used for the skin because of weight. Many canoes and kayaks are/were built the same way.
If the skin is not penetrated, the roof generally remains sound, despite the cosmetic blemishes of the scratches. However, water getting to the foam-skin joint would cause joint failure known as delamination. Cosmetic repair kits for surface scratches are available for canoes and kayaks - color matching is always an issue. Fiberglass resin and gel coat is an alternative, albeit with the same color match issues.
Coleman pop-ups were the leading user of this type of one-piece molded roof. Unfortunately, the molded roofs often weren't strong enough to retain their shape and needed metal bracing added. Improperly sealed penetrations for awning mounts, roof rack mounts, and air conditioners added to the failures.
On my Coleman, I ended up plugging the awing mount holes and fiberglassing with a thin layer of cloth to save the roof. When I remounted the awning, I caulked the holes and under the track.
Aluminum roofs are really an aluminum skin over a thin (very thin!) layer of plywood - usually glued together. Again, water getting in will damage/rot the plywood. This type of roof is actually easier to repair for a DIYer. Rotting plywood must be replaced, and the source of leaks fixed.
Robert's Sales in Denver really knows the Flagstaff/Rockwood pop-up line, and may be able to provide more and better information than I.
hope this helps
2019 Flagstaff T21TBHW A-frame
2022 Kia Carnival minivan