This is the remaining fold-out frame from a sofa bed that we have scrapped. It fixes to the frame within a sofa and sofa cushions dropped on top.
If course to use this you will need to construct or acquire a sofa "frame" to hold the bed, but I thought it might be of use to someone!
The final picture is an example of the frame folded out from the sofa it was originally a part of.
The bed frame itself is 120cm wide by 180cm long, but will need to be fixed to sides that are 130cm wide.