Yes the rudders were predrilled. One was even pre-chipped. Anyone have an idea how to get a look at it withoud cutting a hand hole in the bulkhead. Fiberoptics anyone?
Install a 4" inspection similar to what you forward the rear cross beam. As for re-taping the holes it really doesn't take much in the way of skills - just do two at a time if that will help you comfort level.
If you go the inspection port route you may want to consider a backing plate with nuts - nylock - aircraft my recommendation.
