The Devon Motor Caravans Manual
The illustration indicates the removing of the backrest. The seat base is then slid back as far as possible; the base lid replaced at the opposite end, and the backrest dropped in horizontally between rear seat and sliding seat. The cushions are then replaced--these cushions fit very tightly in order that the sleeper may not displace the cushions during the night. The illustrations on the opposite page [page 5] show the single bed fully erected.