Liking your build.
This question is probably too late for you but I am wondering if anyone has considered making the lift panels out of Aluminum plate or welding up something. It seems to me that they could be light weighted with cutouts that would also provide access to the inside of the canvas behind the lift panels (where it is hard to keep clean and wipe off condensation to prevent mold growth.
I suspect Aluminum might be lighter, stronger and importantly less prone to degradation as well. I have done no engineering related to doing this so perhaps there is a good reason I have never seen anyone do this.
Craig
I made a set of lifts for my Fleet out of 3/4" square steel tube. I wanted 34" of lift so I could stand up plus a little extra room. It's sort of based on the electrical conduit design that's floating around wtw and expo, but folds more flat so it doesn't eat up matress storage space. It's posted on expedition portal in my Fleet flatbed conversion thread (my only thread on expo, same user name). I'd call it version 1: works, but I would invert the mechanism, and make the hinge mounts beefier.