Slogged through the "deburr, match drill, dimple, cleco and rivet" routine to get the bottom skin in place.

I regret that I didn't spend more time getting my helper up refreshed on riveting. It's important to just hold the gun firmly in place and let the tool do the job. He was trying to force the gun downward, got off perpendicular and the tip slipped, even with a rubber booted flush set. So now, I have to admit, my airplane won't end up being perfect...ha.