Very interesting, lots of good photos. We had come to the idea of putting a sofa/bed combo across the back already...This system looks quite complex, though Paul says the slat system is do-able, I think it's more likely to get done with the plywood Bob Miller suggests. As for that, what kind of a "double" bed is six feet wide?
The IKEA futon idea is good if you've decided you're never going to want to cut it to make a traditional dinette area...which we're pretty close to deciding...we already got a twin, all-foam, 7" IKEA mattress in the clearance area which will be on the front gaucho bed as a bed only for a while, then cut to make a bed-length sofa in the daytime. the back bed will be the same, with a slide-out gaucho section added and better lids and interiors for the original storage "bins" under the dinette seats/back bed. Neither area is standard for twin (front, length too short) or double (back, width too narrow) but since we gutted the shell, we'll rebuild the "furniture" to make things more standard. Eventually we'll have a folding 4' table for the back and there will be two sofas during the day. Naturally, the covers will be removable for washing (with two pug girls, it's inevitable) and we kept the beautiful, super long, heavy-duty zippers from the old upholstery covers--the PO had something like 9 or 11 cushions to make up a complex of two beds...neither of us ever managed to figure out exactly what configuration got us to proper...so my design has only four cushions at most. The covers will be joined but removable for ease and washability without wondering which goes where. Interesting about the height--we may want ours to be "lower" than before--would be better for the pug girls, too, but we'll see.
All the optional configurations shown in the link are very interesting...very. Probably going to keep ours more like original amerigo
except for very rear sofa config...nothing fancy, my mind just doesn't wrap around that any more, and Paul's carpentry is good but basic.
Still, good to see, thanks for sending it on!