70s Six-Pac, trying to figure out how to run new plumbing

As best I remember our bed was full size, but it seem short. piano hinge across the front and a couple of hooks on the walls to keep it out of the way. Had to manually lift it out of the way.
we used the 2nd truck battery for the lights in the camper.

The other thing was the gray water bucket was outside on the ground and a hose ran into it from the sink.

We did not have fridge used a cooler and ice.