Opened up the holes for snap bushings where rudder cables pass thru the F804A and F840B center section assemblys. Like other QB builders, discovered that you can’t get at the hole in the rear bulkhead unless you remove a nutplate. Drilled out the rivets holding the nutplates, then opened up the holes for the bushings to 5/8”. Threaded the rudder cables, added snap bushings and then added nutplates back using cherry pop rivets.