Cut some 3" sections of MS20257-5/4 hinge, (plans say MS20001), so secure rear seats. Consider same for front, but stick cover/armrest may prevent this sort of removal so didn't.
Recessed rear edge of port thigh support and both seatbacks for the hinges.
4 x BID over the thigh support hinge points, peel plied edges and clamped -5 hinges over the top, joined by a greased single pin.
5 x BID over the seatback hinge points, peel plied the edges.