We replaced ours with a Lazy-Boy sofa bed. Our original sofa bed had a twin bed in it and we wanted a full bed. Probably a more costly fix then you are looking for.
Some folks put an air mattress on top of the existing mattress. Makes for a pretty high bed though.
Replaced with a Lazy-Boy Diana Supreme Comfort Full Sleeper Style number 500. Just fit in the door going in vertical. We took out the old sofa and the delivery folks put the new one in the RV. The back came off on the original sofa but does not on the Lazy-Boy. Our 6' 2" - 210 lb grandson said it is much more comfortable than the old one sofa bed.


We lost about 4 inches between the dinette chairs and the sofa. We switch the location of the sofa and recliner chairs when we get to out camping location (use nylon gliders so the moving is easy). We put a mattress pad on the new one too - it adds a little more cushion.
