I spent the morning with a storm blowing through, finishing the riveting on the open rivets as called in Section 13, Step 5. Then prepped the doublers for the rear spar and clecoed then, per Section 14, Step 1.
Unfortunately, I do not have a 120 degree countersink cutter -- although the RV-7A countersinks with 100-degree cutters, so I'll order that from Cleaveland Tools today.