We had one almost exactly like that when we were station in Alaska, but ours was for an 8 ft bed. the over cab bed tilted up so you could get into the dinette, there was a jug of water under the sink and a hand pump faucet. we had a bucket that the water ran into that was dumped away from the camper. It also had a porta-potty that fit into a cabinet had to be pulled out to be used. We traveled all over Alaska some wonderful memories.
We had it in the back of a 1976 F250 with the 300 6 and a 4 speed manual with 4 wheel drive. My wife had to stand up to push the clutch in. On a good day with nothing in the truck, but us, with a tail wind and going down a hill, we got 8 MPG, fully loaded in 4 wheel drive going up hill we got 8 MPG. with the two gas tanks we carried about 38 gal. The only real mods were the air filled rear shocks and duel battery. of course it had a block heater, the stick on transmission heater, electric interior heater, and the radiator heater. This truck had what was called assisted power steering, it had a power steering power cylinder installed in front of the front axle, and driving to work some of the winter mornings with it 50 below the fluid was so thick to took everything you could do to turn her.
When we were transferred back to the lower 48 we put the truck and camper on the base for sale lot and it was sold within an hour.
