Finally, I drilled the hinge holes with a number 12 drill for AN3 bolts which is about 0.186 inches per my calipers. Then I installed the hinge brackets and torgued the bolts to 25 inch pounds. I put inspector paint on the bolts to remind me they have been torqued and to show if they ever come apart.
I had to file down the sides of a socket in order to get it on the head of the bolts in the skinny hinge bracket. Then I put it on the wing and moved it. This is the fun part. The gap between the top skin and the aft end of the main wing skin is about 1/4 inch and constant its full width. So I think this installation will be just fine. I'll do the final installation after assemblying the flap, per the plans.
