Reddit mentions of Special Products (Speeco) S010541GT Hd Ratchet Jack Hitch Accessories for Tractors, 28-Inch

OK so the spring/coil unit wouldn't need to be hinged. It could be two legitimate pieces (his + hers), in the same way that a king bed can be made from two twin's today. They'd still both go within one fabric/foam wrapper. You'd clip them together before you zipped the whole thing up. The zipper's a neat in this case because you'd still put fitted sheets on the whole thing, and they'd be hidden even more.

Do the springs come from China in mattress shape, or it is pure spring metal packed for density. I'm trying to imagine those expensive containers docking in Portland/ San Francisco. So in most cases it's assembly in the US (or Canada). I had previously imagined you'd receive drums of wire, and make coils yourselves.

You joke about getting into the mattress business :) I'd previously been sketching designs for a standardized sofa and chair assembly 'model' also imagining soft coverings coming from the far east, and being assembled at home. In that case the sofa frames (say about three or four standard designs would be made from 2x4 (or similar) locally, but have a mechanism of tightening the frame within the fabric cover. That would allow no external zippers, but still a taught product that could be home assembled. Specifically the wooden frame could be tightend whilst being assembled by virtue of a ratchet jack - http://www.amazon.com/dp/B001TPYX9O - Either that was built-in, or is in-situ long enough for some of the wooden bits to snap "home". again the soft coverings could be ordered from a catalogue and delivered by UPS in a box, the wooden frames would be made on a jig in a local factory, and delivered through regular furniture channels or direct from the factory. The arms would clip on much more simply, and probably be modular in themselves versus the base. They may or may not come complete with the soft coverings. You get the added benefit that the whole construction thing can be reversed to got larger items out of smaller apartments or high-rises.

I'm just a software guy though : You're my only contact in the furniture industry :-P