This step shouldn't have taken 2+ hours, but it's been so long since I've driven a rivet that I put them in upside down and had to drill them out because they didn't have enough clearance! That done, the ailerons went in smoothly and the counterweight hangs them just where it should. (The photo here looks like it's trailing-edge-high here - it is! That's because the wing is angled on the foam blocks I have it resting on.)