I grew up in NZ before coming to Australia, Michael, I visit there every couple of years. There's a popular aluminium boat in NZ that I've noticed called a "Stabicraft" with a hull that's built like a transition piece. No stretch or expansion, the plate is cut, bent and welded. Probably not the slickest thing through the water, but it must be easy to build with unsophisticated tooling, like a marine Land Rover or Jeep.
*edit* an unfold/flatten tool for general ruled surfaces is one that TC's still missing. You say that the joints are circular, so they can't be conical sections, current unfold won't cooperate.