Cruise control with manual trans

All cruise controls have kick-off mechanisms; for an auto, it is the brakes only and should have a sensor to detect any movement of the gear selector. For a manual, it is brakes OR clutch OR a movement of the shifter out of gear that kicks it off; the last sensor on the shifter is the trickiest for a retrofit installation.

And, yes, there is a vaccum opearted servo which is used to actually work the throttle, and an electronic control module that controls the throttle via this vacuum servo.