First thing I did was take out everything... all rivets, all cabinets, and replaced the wooden floor where it was rotten. I cut 4" round drain holes into the floor front and back and then spent days scrubbing with tilex, ajax, and simple green and a garden hose on high pressure. The floor holes I cut allowed the water I was spraying inside to drain out whether it was ponding in front or back depending on the tilt of the trailer. I then put 4" PVC plumbing screw caps into the drain holes to serve as plugs for the floor drains
After that, I linoleumed the floor and installed all lights
. I found surface mounted tail lights
for which I cut holes and they don't protrude at all. See picture. I added electric input to charger/inverter and battery
. Rebuilt door: removed interior skin that was sloughing off, remounted and sealed door window, epoxeyed old hinge mount holes and remounted door solidly. Pain.
Did find nice marine epoxey paste called PC-11. Highly recommended.
Cut all new cabinet doors and table from Birch plywood and put many coats of finish. New cabinet hinges and re-riveted everything back in. Used PC-11 in every rivet hole to assure of permanent seal.