I would LOVE to see your lift bar solution and details from building it.
I'm redoing a 1986 Keystone and the lift panel over the bed had water damage and whoever tried to fix it before didn't reuse the rivet holes and drilled new holes to put screws in. The entire thing is a massacre. I'm worried about trying to remount the panel (after I rebuild it or buy a new one) and having the integrity of the mounting spot so compromised that it doesn't work. Thinking of replacing the panel in the front with a lifter bar of some sort and maybe just keeping a panel in the back only. (Though I like the more minimal solution of a lift bar).
I'll get the detail out soon on the lift bars that I made(I did take a funny video, but forgot to take pictures and don't know how to post a video on the site).
I too have been through the lift panel rebuild "massacre" as have many before me ! Though my forearms could use the "rivet workout" I just wasn't into redoing lift panels again ! I would however say that provided a rivet gun, some hinges, and wood, it's pretty easy to do when short on tools (just really undesirable in my opinion)
Any possibility you could tack weld some 1/16' strip aluminum over the existing holes? Additionally, if its the bottom hinge area that's trashed, you could throw a strip behind the plate facing you, then go nut and bolt ... If its the top hinge area - I get that's a bit more tricky (but that's where I would tack some new fresh sheet metal and keep the mounting point for the quick and easy redo)
The new bars that I made, I did weld at certain points and used a tube bender - So there was still a bit of work, but way worth it. Again, i'll post details and pics after the 3-day!