Had options to handle the flap hinge and I chose to split it on each flap and remove 3 eyes to feed each side in from the middle. I made retainers from surplus hinge eyes. Using two opposing hinge eyes, I double flush riveted them (they really only needed to be flush from the back side which hugs the flap spar when tight), rounded the corners, and drilled the #19 hole for the #8 screw. Notice that even if the screw worked itself out, the retainer will still hold the hinge pins together. Those hinge pins aren't going anywhere. My biggest decision was whether to mount the nutplate on the flap spar or the flap brace. I chose the spar. When I disconnect the flap tube and rotate the flap fully down, the retainer is very accessable.
Placed one hinge eye on top of another and double flush riveted them together.
Feed the hinge pins in then slide the retainer over both.
