[monocoque]

Originally Posted by Wabbiteer

The 3" channel extension is black-tank area & must likely be duplicated; that said, it also formed the hose-storage trunk at the rear bumper on many model trailers but I don't see the 12-inch plus extension of the frame past the shell that makes up the trunk area.

'Sculpted relief' is 45 or 60 degree slant - something like notching the beam sides out and hammering the bottom up to meet the new angle to be welded...

Look closely at the last photo in post 224 and I think you will see the 12-inch extension of the frame past the shell. It's the area painted grey and the rusted area is the area usually hidden behind the banana skin and directly below the shell. The bumper is still attached to the main rails in the photo. (Wow, those were the good old days!)

If I remember correctly the 3" skid serves as the attachment point for the black and grey tank frames. Actually the frames for the tanks are connected to the skids by steel tabs that have been welded to the skids. The tank frames are connected to those tabs with bolts. The material from the old frames is still in good shape so we will be reusing it.

I see what you mean about the angle of the cut. The rear ends of the main rails are square but the skid is actually cut at a 45 degree angle. The welder is using the old frame for a pattern so no worries.