Today started by framing up the rib pieces for the right horizontal stabilizer, then wrapping the skin and clecoeing it all together. Next I clecoed on the rear spar and started to fit the innermost rib pieces which weren't factory drilled. It took a lot of math and reviewing what other builders had done, but I'm happy with the results and had no issues with the flanges there. Finally, I clamped the inner ribs and drilled them to match the skins. I have one more step before taking the skin back off to dimple, and that is match drilling all of the holes except the inner ribs. I'm excited that it's starting to look like airplane parts!