I continued with the hand squeezing of rivets tonight, first starting with the double-flush rivets that hold the two halves of the flap hinge brackets together. The double-flush technique is an interesting concept, but I wasn't able to get it to be completely flush on the shop-head side of the piece.
I then continued to rivet the ribs, nose ribs, and flap hinge brackets to the flap spar, still using just my hand squeezer. A few of the ribs were a little tricky to get access to, and I had to reverse sides that I put the shop head on for several of the ribs in order to make squeezing easier. Unfortunately, I had to end the night with one of the ribs un-riveted because it was simply undoable with my squeezer due to the proximity to the flap hinge brackets. I suspect they'll be easier to rivet with the pneumatic rivet gun and an offset bit, but I'll have to figure that out tomorrow.