The Moonraker interior has 1 buddy seat that folds into 2 behind the front cab seats, I have a copy of plans for a full devon moonraker interior PM me your email and I will try and send a copy.
My 72 has a single seat which slots between the two seats up front. It then acts as support to one part of the mattress when the bed is put out low down, and jams the table into its slot by pushing on the legs. It doesn't fold or anything though.
If you are at Volksworld on the Sat you can check it out.
Thanks guys, i'm hoping to get the bus through its mot this week so i will need to put some sleeping equipment in it ready for the shows. I'm thinking of constructing a devon bench seat in place iof the buddy seat because it allows a lot more storage for bedding and provides seating for my partners smelly little westie Molly!!!