With the van tapering in the rear the bed area is 75" on one side and 72" on the other. I also custom designed the frame to be 4' wide (in between a twin and a full) to maximize the livable space while still being large enough for 2 people.
I needed a custom sized mattress and thus bought a full size memory foam mattress (75" x 54") which didn't contain fiberglass, and cut it down to size. With the tapering of the rear, I debated whether I should taper the mattress as well or keep it a rectangle so I could flip it around throughout its use. In the end I decided to keep it rectangular and cut the entire length down to 72". At this size it's still tight, but the foam contours and compresses fairly well for it to fit. Once I get sheets and a comforter in, though, it may prove to be more difficult .
I then cut the fire sock to the new mattress size and picked up a handheld sewing machine to close it back off.
Near the foot of the bed the interior metal sheeting extended a few inches above the plywood base. I used my angle grinder to cut it down below the plywood so it wasn't pushing on the mattress. This gave it another inch or so and allows the mattress to slide in easier. This will be re-insulated/ capped once I start on the interior
I also fixed a few of the cracks on the windshield. If you look closely you can see the cracks disappearing around the plunger