Piano hinges join to the wing, Dzuz fasteners for the top and bottom arches. See attached write up. The stronger extruded piano hinges are pricey - $37.50 each, but they are stronger, lighter, and look better than the alternative of Camlocs. Now I'm paying the price for a deviation from plans + the custom cowl. _Lots_ of tweaking has happened. Constantly moving above and below the cowl proved to have its own risks - three weeks of wearing a bandage after I barked my head against a cowl edge.