Good suggestion Mike, but believe it or not, this little ten minute to fabricate tool was easier for this specific task than my strap dulicators. The skin is stretched pretty tight between the spars, which are drilled first and clecoed down. I wanted the best fit as possible and the thickness of the strap duplicaors has caused problems for me in the past. I am not a big fan although they do have their place.
I thought of drilling the ribs first and back drilling, which is very doable on the end ribs, but my Jig bracing was in the way. I chose this approach so I did not have to fight with my Jig, and it worked well.
Bob - you dont need a tool like this unless you are building a 3, 4, or very old 6. The new kits have taken away some of the creative thinking with those fancy new computer made prepunched and matched holed cleco and go models