Campers are easy to fix, and replacing entire sections can fix any problems. Will a dealer take the time to do this? Likely not. I would trust an individual much more than a dealer.
I have done RV repair - rip out the bad stuff, put in new good stuff. I have pulled out rotten soggy wood and the repair is better than new, but I have also done repairs to less important areas and the fix was less than new. Some areas just do not need to be 100%. I have done roof fixes on my camper and left gaps where there once was continuous plywood, but these areas did not need the extra strength the wood gave. I feel 100% confident in the repair too.
The point being that repairs are easy and there are places where a mechanic can skimp and it totally not matter one bit at all for any reason, but there are other areas that are important. Knowing what to look for is key.
Don't be so much concerned about the repair, but if the repair leaves the unit in good enough condition to last the life of the camper.
For instance, a water-damaged floor that has been dried out, the leak fixed and instead of replacing the entire floor the mechanic reinforced the floor underneath, leaving the weekend wood floor in place might be fine. The floor will still hold up the person from above and you will never know it has extra reinforcement holding it together (making it stronger than new). What more does a floor do?
Your camper can be patched up many times and function 100% to your satisfaction.
Mold on the other hand is another issue entirely.
