Harry, we had a Cameo that was getting some flexing at the area forward of the bedroom slide corner. Water had gotten in and weakened the structure. The repair was to stiffen the area around the slide cutout. The repair was done by Kansas RV Center in Chanute, KS and was about $2700.00
The trailers that use the laminated side wall construction depend on the glue and sandwich construction to provide strength. Once water gets into the wall, the Luan plywood lets go and the wall looses strength.
SO just dropping the over hang bottom and adding metal may not cure the problem and will require a sidewall repair as well.
You need to decide if the expense of the repair is worth it on a trailer of the age of yours.
Ken