Here, let me complicate things further - how about having the passenger end swing open like a door, hinged on the box side. Simple matter to form some flat strapping to fit at the seam, parallel straps, epoxy and glassed in, cutting the shell between them. Then there's no heavier framework, lifts actuators etc. Do a lightweight aluminum L-channel perimeter framing for mounting and rigidity. Then you've got easier side-access to the full space. Make it accessible from the bunk area too, sliding panel.