This evening I got the right wingtip drilled and clecoed. I had to do some additional trimming and sanding on the tip flanges and leading edge to make it fit well. It still will need quite a bit of work on the trailing edge to make it line up with the aileron. I'll also need to tweak the fit slightly as I drill the holes up to final size.

Photo 1: Beginning to drill and cleco.
Photo 2: Here's how I used duct tape to pull up on the tip while drilling the attach holes.
Photo 3: Wingtip is clecoed on to check the fit.