+1 for Dave
I was trying to remember how I did that row of rivets. I think it is the outside skin bend tends to pull that area out if it is a little under bent.
I had the same problem and solved it the same way. I used two and walked them along the row pulling things in line and adding clecos. HF has a nice set for about $5 I use all of the time to line things up for riveting, fish wires thru holes etc..
Building my RV-10 since Oct 5th 2014
Flying .. once I figure out how to pay for everything
Dues paid 2018