Stand inside, at the rear first, push it up, swing up angle iron on a hinged system. Angle iron is cross braced for rigidity. Once that's done, hop up on the bed, lift the front up, swing up 16" tall legs into position, just like back. I might stabilize it on high wind days with rope, like a tent. It's pretty secure, but Utah can be violent at times.Can you provide some more info on how the top is lifted and secured? It looks you have a very simple system, which is great.
ABS Plastic 11lbs per sheet x 3.5 sheets=39 poundsHopefully this is going to give you some ideas
I still think you're going to need airbags for the rear but that's 70$ fix+air