Faced with the nice camper that sleeps 4 and having 5, and neither of us wanting to stand watch over a "tented teenager", we worked out this which is pretty close to what ive seen of the original hardware. I gingerly tested it to, um... lets say 130 lbs but im planning to put a 40 l kid in it. Big kid gets the bottom.
Coleman Ridgesomething 2 cot from Walmart .. it has a foam pad and nice springy bits $43
4 nailer plates $4
2 Chain link gate tension clips $1.10
7 feet chain $5
2 saddle brackets $6
4 split links $4
3 copper couplings $3
2 feet 3/4 copper $8
Old nasty used hacksaw blade cut to size with teeth ground off
And a whole mess of rivets
We modified the cot.... it originally sagged in the middle at the hinge, so we removed it. 3/4 copper slid right inside the tubing. Used one entire and half another 3/4 coupling as a spacer to take up the distance lost by the hinge. He soldered the insert pieces to themselves before installing it. To get it in we unclipped the springs on both ends. It was something like assembling drum brakes forcing the springs back on after the frame was rigid....
Its easy to find the ribs for mounting... thats where the rivets already are holding the paneling on.....
I had the horrific visualization of the kid flipping the cot up to climb in so I used that bit of toothless hacksaw as a retaining clip sort of thing.
There is about 2 inches of play between the bottom of wall mount lights and the top of window hardware. I was annoyed that this landed high in that range.... measure fifty times drill once.
For my next magic trick im planning to sew chain sleeves and a "rail" between them so the kid doesnt roll out. I think this turned out well, I hope those of you who dont have 50k for a whole new airstream can use this info.