Sorry, but the pictures of the rear assembly were lost, but you can get a reasonable idea from the last three pictures. The sides will drop down to 90 degrees to the lorry, held by some very large chains to give a quite large flat area, which is what was planned because beleive it or not, the back is used to launch fireworks, and i dont mean what you buy in the shops! I work for a fireworks company in Selsey as a hobby and we used the lorry for a show, launching 10 and 12 inch shells, it bounced a bit, but was otherwise unharmed, hence the name SPARKY.
So, i finish with a before shot, and 3 of us arriving at Dorset up the playpen last year.
Alan.