What to use for pull pull cable exits?
You don't need to go to all that trouble. Get a piece of piano wire about 3 feet long. with your servo and all horns in place and wing off; lay the plane on its side and position the piano wire exactly over the servo horn and control horn and mark the up-down location. then tuyrn the plane upside down and do the same thing to the left-right (front-back) location and you are all set. Sounds goofy, but works pretty well.