I have just gutted the interior of my '78 sovereign
(doin' the full monty).The wall you refer to in mine was the side of the cabinet and part of the bed frame and overhead bin were connected to it. The cabinet, bin, and bed were connected to the wall with screws accessible inside the cabinet and under the bed. The partition wall was riveted into an aluminum channel that is screwed into the exterior wall. The partition walls also held up the kitchen/bedroon door track.