Hey Matt - as we hijack this thread - I can't post pics in "conversations" for whatever reason, so here are a couple of pics showing the cable tube and its' locating nub in the slot in the servo housing.
For the sake of others reading this thread and dealing with removing and reinstalling the Autopilot dash dial cable as it goes into the servo units:
The tube the cable goes into needs to be removed from the servo housing and can be a bit of a beeyotch.
The tube is a press fit with a little locating nub into the servo body, and often corrodes in place since the servo is white metal and the tube is cad plated steel - dissimilar metals reaction dontchya know. Anyhow, it needs to be twisted out of the body of the servo to expose the internal part that the ball end of the cable sits in. When you turn the cable it pulls or pushes on that internal part and slides back and forth inside that tube... On my servo you can see a channel that the nub locks into.
Use a strong pair of long handled roundmouth pliers - wrap a cloth around the tube if you're concerned about marking it (I just polished mine up afterwards before reinstalling it) twist left and it should come out.
Slide it down the cable to expose the ball... installation is in the reverse. Like heat shrink tubing and wiring, you need to put the tube over the cable before you reinstall
!! 
On the picture of detmatt's servo, I see a screw tucked away at the base of the tube - I can't tell if that's to hold the tube in (an improvement over the locating nub version), or if that's to do with the servo motor behind it.
