Did you put a new square 14 inch gasket to stop the leaks? You have to put a new one on every time.
It should not leak, those gaskets do not leak when new.
I have seen window AC units on RVs. You would have to have an inboard one, so need an inside cabinet to hold it and be big enough for air to move on the sides of the cabinet in and out. Just put big grills on the opening so the air can move. This is the air that cools the compressor radiators (this air does not come inside, inside air is always recirculated)
You could put it on the top half, but having rebuilt those walls, I'd say not to put that weight hanging on the wall pulling it out.
I wish all RVs had side mounted ACs, I hate the extra wind resistance and clearance issues the roof things cause.
I just took mine off of a truck camper Im working on. Plan to put back on in June in a better spot so no roof sag.
I used a long extension ladder as a ramp. I had a side hill to make it easier so that kept the bottom of the ramp 3-4 feet higher than the tires. Use a small board, bigger than AC footprint, and slide it up or down the ladder ramp.
Put cardboard on the roof to protect it. I also put a board on roof to walk on and be there to move the AC on so no roof damage.
See my rebuild thread if you are having sag issues on HILO. I put an inside brace just to be on the safe side.
one of these threads has pics:
http://www.hilotrailerforum.com/f25/...of-holes-6069/
http://www.hilotrailerforum.com/f17/hilo-renno-6007/