Look no clecos! A few of the rear spar rivets are still not in near the root; it seems these will be easier to squeeze once the wings are out of the build stands.
The easiest way I found to do this was from the trailing edge. Starting with the center rib of each skin, I would rivet the skin to the rear spar between the two center ribs. Then work up from the trailing edge on each rib. I could just reach the fourth rivet above the J stringer by laying on a creeper.
After each skin was done on the lower portion, I would then corral a helper and rivet each rib the rest of the way up and then the main spar. I found a helper with a tungsten bucking bar was the easiest. I also used a wi fi endoscope camera hooked to my iPad so I could see around the other side and validate each rivet as we went. For $40 on amazon, the endoscope camera was well worth it. After a while, my friend would understand a good rivet and we would move along.
I took advantage of my rivet buddy not wanting to go home (because of traffic, not the wife, so he said) and was able to get all the top rivets on the right wing too. The rest I can get from the bottom with a creeper.
The wing is going slower than I anticipated, but I am taking my time and keeping the quality up.
After checking the twist, everything is as before. I did notice the right skin had to be cleco'd in a certain order to get all the holes to line up, so I ended up clecoing the skins on twice and using a cleco in every hole. There must have been some sag the first time. I am glad I didn't start riveting until both skins were on and fully cleco'd in place.
(Wow the shop is a mess!)