Ken from Van's answered my question yesterday and said it'd be OK to redrill. I decided to redrill the aileron bracket plate rather than the rib holes for two reasons:

1. I want to put the manufactured head on the thin material, so that means the shop head is on the bracket plate. With this arrangement, I think the rivet is more likely to fill up an enlarged bracket plate hole than it would be to fill up an enlarged rib hole (directly under the manufactured head of the rivet).

2. If I screwed it up completely, it would be a lot easier to remove and remake an aileron bracket plate than it would be to remove the outboard rib.

As you can see, it came out OK. The plans called for AN470AD4-6 rivets here. I ended up using -6.5 rivets for the middle and right most holes.

Unfortunately, in the process of redrilling the aileron bracket, I bent my long #30 drill bit. Have to get another one at Oshkosh I guess.

After that, I match drilled the aileron gap fairings to the skins. I had previously match drilled them to the rear spars. Then it was just some quick deburring, dimpling, and rivet squeezing to get them installed. Here's the one on the left wing.

...and the one on the right.

Side note: I've gotta remember to reinstall the eight or so inboard rivets that attach the top main skins to the rear spars before installing the flap gap fairing. I had taken those rivets out the other day to drill/deburr the skin, wing walk doubler, and #1 rib for the wing fairing attach nutplates.