Re: cruise control box.
You should go back and grab the short speedo cable that come out of the cluster and connects to the rev-counter. This part is hard to find and no longer available.
If you want to add cruise control, you could grab all the wires and components: wire harness, rev counter, brake switch, clutch pedal vacuum switch (if manual), the "thingy" on the firewall that controls the throttle, the "football size" vacuum bottle (behind the front bumper), and all vacuum lines