See the attached EX40F pic, which is also in the files section under EX40. Also attached a zoomed in version of it.

You can see it is just a hinge for 2 beams. One beam is a C section. The other is a box. Very simple.

I think the C sections will be buried in each hull, and stick up in the air when folded under. The box is between the two hinges, perhaps roughly horizontal, depending on how far along the beam the hinge is needed for the geometry.

There is a problem with height, but it should allow rather wide boats be trailerable. Boat is oversized anyway, so over height is not that big a deal, I imagine.

I am kinda crap with 3d rendering. Hope that helps.