Any tips for re-stretching or replacing sagging wall vinyl in 90's model Carvers? It appears to be a common problem.
It may have been installed using contact cement. Try applying heat, using a hair dryer on low setting. Keep moving it around to avoid burning. Then press by rubbing with your hands. This should reactivate the glue. Good luck.
Some material coverings had a mat between the finish treatment and the bulkhead. The finish fell like ole Rose; https://en.wikipedia.org/wiki/Mary_Millar You may not get enough glue in between the bulkhead and the finish cover. You may consider a new bulkhead cover entirely for your taste.