After a long break, and time to think, I have decided to abandon the idea of the fold-down design. Its just too complicated and I have many concerns about how watertight it will be. So I tore down the back wall and have begun rebuilding it on a rigid frame. I'm also roughing in some of the interior features and figuring out how the potbelly stove will fit..
This shows one of the benches. It is wide enough for two people of modest girth and the bench doubles as storage. The curved back is made from African mahogany. The square hole to the left of the bench will house a cabinet with drawers.