Tonight started out by cleco'ing together the nose ribs, nose skin, and spar of the left aileron together so that I could match-drill the counterweight. The counterweight is actually just a stainless steel tube positioned at the nose of the aileron, but it must be match-drilled in 14 places and the final-drilled to the needed size.
Drilling through this stainless steel tubing definitely took some life out of my drill bits, and I had to switch to a newer drill bit part way through when I realized that I was making really slow progress drilling. Fortunately, I stocked up a few spare drill bits around just for this reason. I'll just also mention that it was very nice that Vans pre-cut these counterweight tubes to the right length at the factory, because cutting them to length (as the instructions says you might have to do) would have been annoying to do with just a hacksaw.
What's next? Assuming my new bandsaw blade arrives tomorrow, I should be able to resume work cutting out the ribs for the trailing edge of the ailerons. I might also work on doing the same steps from tonight on the right aileron.