I'd call Precision RV in Bremen, IN. They paint coaches and should certainly have the capability to do those repairs. If they can't/won't do small jobs, they may be able to recommend a shop.
As noted, anyone who does fiberglass boats could do it or any collision repair shop that can handle a Corvette. Many auto body shops can do the work but don't have the facilities to handle a class A coach.
Another option is to call a Peterbilt, Volvo or Kenworth truck dealer. Most of them can tell you who they use to do similar repairs on their trucks.