This is the shape of the cushion for the rear seat.
It turned out to be opposing 10" radius bends so I tried a different method to make a pair of pullmax dies. These came with the machine, but were an odd shape, so I set them up mirrored in the CNC mill and cut the radius internal and external with an arc program by moving the X center but retaining the Y center.
Then I used them to form the rest of the seat bottom and welded it to the left hand piece.
I mocked up the seat foams to trim and reposition some of the internal wire frame.
I replaced the original floor and added some beads to stiffen it and then rather than lose that space I added a hinged access to the underseat storage area.
The cushion is held with retainer clips at the two rectangular slots and lifts up easily to get to the space below it. I had thought the curvature was enough to stiffen it, but had to spot weld additional ribs next to the opening.