I started out tonight's session by moving the right wing's rear spar to my drill press and doing a final size ream of the bolt hole in the attach bracket, with some Boe Lube for lubrication. A little deburring around the hole surface on both sides, and then I was ready to cleco it back onto the wing assembly and start riveting.
All of the remaining rear spar rivets that I needed to set were all doable with just my hand squeezer and the longeron yoke. Since there were several different length rivets that needed to be installed, I did have to readjust the squeezer depth multiple times.
After the squeezing was done, I pulled out the top skins and the wing walk skins and clecoed them in place to prepare for the next day's work.
What's next? There's some match drilling required of this top skin and wing walk area, and then probably a lot of dimpling.