I've got an original "RAF" type lorry chassis, if anyone needs photos or measurements. It's the heavy tender. It weighs 4 tons and carries another 3. I have seen photos of aeroplanes being loaded onto them. One of the photos I have is of the AWM's Albatros being loaded onto one! When I worked at the AWM they were restoring theirs, and we worked closely together to achieve this. They obtained drawings for the tray, which neither of our vehicles still had. I am not sure if the drawings are available from the AWM, but I have often wondered, and I could ask if anyone is interested. Mine has the cab, although it is very rotten and rusty, as would be expected from a 100 year old vehicle. A good percentage of the cab is timber, so it is a miracle that it has survived!