Has anybody found or used anything that might work?
During my 2005 cross country trip from San Diego to Oneida Lake in central New York, we lost the door off the hatch below the curb side bunk.
My Dad suggested looking for an RV dismantler, and we found a place that sold
new and used
parts. There was a store in front and a junk yard in back, and we found a large 5th-wheel trailer with a huge compartment door that I removed and bought for $15. I disassembled the component parts and kept the skins and extruded aluminum frame, discarding the wet fiberboard core.
I cut down the extrusions to the sizes needed and reassembled the door to fit.