Spent a few hours working in a cold hangar this evening.
Basically I completed the four spar-web flush-mount rivets. They came out just fine but next time I will use the pneumatic squeezer. Using the main squeeze hand-riveter left me without an extra hand to push in on the flush side of the rivet, hence it did not seat as perfectly as normal. I also primed the countersink prior to seating the rivet.