So if one wanted to rehab a Class A M.H. that has much delamination and a roof that leaks, how can you replace all that material and stop it from happening again down the road. I say this because the ...
This sounds like a complete money pit. Water is a killer to any structure. Even if you fixed it I would still be concerned with mold and structural damage. The amount of money you would spend would be lost because it will never be worth what you put into it. I would estimate the cost of the job (likely well over $10k) and take that money and buy something that is in decent shape with no leaks. Plenty of used Rv's out there.