The next step is to get a sheet 2400 x 1200 x 3mm folded to fit in the floor under the hitch. This will join the rear section to the front subframe and provide a little rigidity to the tray. I will also get two pieces 1200 x 460 x 1.6mm rolled to half circles with a 400mm radius to form the inner wheel arches.
As it is Christmas and most of the businesses around here are closed till early January, I will have to wait till I can get this done ready for Part 4.
Now to sleep on what I have done and work out the best way to cover the shell.