Thank guys for the posts. I think I'll switch my rudder hinges to the traditional type.

In regard to the Ailerons servos. I decided to open up the already relieved slot in the wing toward the servo rib. This made a perfect rectangular hole for the 9151 servo. I then made some 3/8" x 3/8" x 1.125" bass wood pieces, and glued underneath the wing skin (where the servo screws would be), and butted this against the original servo rib. Using a $11 "hot-knife" from Tower, cutting the servo holes couldn't be easier or for me, more accurate. I also did a similar installation on the elevator servos. Now, both the elevator and aileron servos are vertically mounted, easy to install, and line-up correctly for the stock control surface horn placement.

In a trial fit, the metal sullivan 4-40 clevis' fit in perfect to the phenolic horns, with seemingly no slop.

You may have already figured this out, but for those of us who are "rudder-cable-hole-exit-location-impared", an easy way is to think of it like this. The rudder horn hole-to-hole width is 2-5/16". If I match the rudder servo horn dimension to this 2-5/16" width, and mount the servo on the center of the fuselage, then the cable should exit the fuselage where it too is 2-5/16" in width. To find this, just glue a 2-5/16" piece of balsa to a long stringer, and stick it down the fuselage until it rubs on both sides. This at least takes care of the "x" dimension.
Jim W.