The replacement floor stiffener came yesterday, and I've been thinking quite a bit about a way to match drill this by myself. After a while, it dawned on me that I didn't really need the skin in place to match drill to the firewall and the center section flange. That stuff isn't going anywhere, because it's clecoed every which way.

Removed the floor skin, marked centerlines and min end distance lines on these stiffeners, clamped them in place with cleo clamps, and match drilled each end. I've seen build logs where people make reference to holding these with duct tape or wood blocks or what ever, but in my opinion, this is the simplest way to get these dialed in.

While I was at it, I match drilled two more -4 rivet holes just aft of the fuel tank attach ears. On the 7A, this location gets two bolts match drilled thru into the fwd brace for the MLG weldment. That part doesn't exist on a -7, and the prints just show you ignoring this area. Seemed like a pretty big span to not have any fasteners in it (about 3"), so I had contacted Vans. Kevin Miller in tech support said it was good either way, but that he had continued that rivet run by installing extra fasteners on his own airplane. Based on that, I laid out and drilled for two more rivets on the same 1" spacing in the location depicted in the attached picture by the red oval.

Clecoed the F-772 skin back on, but ran out of time to do anything else. Tomorrow I'll drill the field rivet holes in these two angles, and then unless I discover something I've forgotten, seems like this whole thing is ready to start coming apart for deburring and prep work.