michael-nola,
i yield to your experience since you have actually done this to a colex, but, normally i would expect an electrical failure LONG BEFORE something was worn sufficiently to be out of round enough to require a lathe. this would certainly be part of the process of a full rebuild, but i would start with simple continuity tests, since the device is "dead". wouldn't you think simply jogging the colex to dead off the "dead spot" would make it turn again, at least momentarily?