[Richard]

Best option, repair what is there. That coach will have Dometic split units. They will freeze you when working properly. Compressors and fan motors are available with parts nos listed on this site. Those units were the forerunners of today’s minisplits. The compressor and condenser are in the basement, and the evap is interior to the coach.

Roof airs would be your next best option

Retrofitting minis into that coach will be tough unless you are willing to deal with the cassettes hanging on the wall.

There is no ducting for retrofitting basement air units into the coach