Here's what I have for a Yokosuka D4Y 'Judy'. The first pic shows maple grooved to receive 'sliders' made of Micarta. There are also some links and levers for a torque rod shown. The next pics are sequential showing how the torque rod drives the sliders. One horn is different than the rest and connects to the flap (not shown). The control surface link is shorter so that as the torque rod spins the shorter link has less motion than the 'sliders'. The flap is top hinged to 'sliders' and bottom hinged to the other shorter link. This is what causes the flaps to droop after they have extended. Takes a little trial and error but is workable. The pics show the wing inverted.