Not much time for shop work today. I removed the rudder pedal assembly and tapped the mounting nutplate on the firewall that I feared was stripped. Tapping it seemed to fix the problem, so I re-installed the pedal assembly and re-ran the rudder cables through the fuselage. Tip: When you install the rudder cables, feed them from the tail forward, not the other way around. Trust me, it's much easier that way. :-O
In order to locate the rudder stops, I mounted the rudder and positioned the cable ends where they will attach to the rudder. I taped the rudder stops to the fuselage sides in accordance with the plans, and realized that the stops will have to be trimmed and possibly relocated a bit. They don't quite hit the rudder bottom the way I want them to. I might even re-fabricate the stop entirely. We'll see. [Superseded with the installation of internal rudder stops.]