One unusual job we had recently was for an adjustable backrest for a large cruiser somewhere in Sydney. The boat owner wanted to have some cushions on the fore-deck so his wife could enjoy the space with an adjustable backrest. We designed a frame that had full adjustment as well as folding flat on the deck. The rest of the cushions lay flat on the deck. It ended up a simple design, but there was quite a lot of thought that went into it.
I am looking for something just like this for undera a foam mattress in my Camper Trailer so that we can watch TV/ read in bed. Two off. Price and availability please.