I knew your cruise control wasn't factory, I remember reading elsewhere. I was just using as a reference where the factory control is as compared to your lengthy cable.
What are the symptoms, that you wan to add lubrication?
I wonder if you could use a cable from a 1985-1988 Montecarlo, since they used a VSS (driven off the speedometer cable, behind the dash) for cruise control. My cable is in 2 parts, so you would need both parts (joined near the firewall), but there might be a single length cable available.