Repeat along the leading edge of the skin on the right side of the rudder. The hinge goes along this edge and you can see it in this photo (not yet trimmed to length).
VS-15 rib in the top of the rudder. This was easier to position than the VS-10 middle rib since I could reach it and see it with the rudder skins assembled.
VS-9 rib in the bottom of the rudder. This was easier to position than the VS-10 middle rib since I could reach it and see it with the rudder skins assembled.