Here are ksdflying's photos and some description:
My mission on this project was to engineer a way to stick with the vans design! ...by driving the impossible to reach SOLID rivets in the leading edge ribs... as the plans call out.
Essentially this process is a heavy steel block (lots of mass) to back rivet against. Using a medium sized ball joint spreader as a pry bar for one person to hold while I back rivet vertically to form the shop head. It worked!
I captured 2 photos of each rib's set of rivets for QA evidence. But for posting purposes, here is 1 pair of pictures (Front and Back) I took as proof of our results on one of the ribs!