Fiberglass delamination on the side is going to be much more difficult to fix. Basically in a nut shell you will have to tear out the material from inside that has delaminated, leaving the fiberglass shell intact. Then you will have to build some kind of support on the inside, and preferably glue the fiberglass shell to it.
Some one built a wood framing, and attached it firmly top and bottom inside the TT, then glued the fiberglass shell to the framing while simultaneously pushing the fiberglass to the framing and clamping it by bracing it against a nearby wall from outside the TT.
I think there are pictures somewhere but you would have to do a search to find them. I haven't a clue as to where you would look to find these.
