Good memory!!!
In addition to the linked thread above...
The burb master switch is a 4-button. You'll need a 2-button switch with matching pigtail (the 'board' to which you refer). That said, you should cull the unused wires from your harness and choose the pigtail based on the switch you're going to use, for example, a
PT188 or PT546 ACDelco for mid-80s vintages. (There may be other sources for the pigtail, as well). Do your research and procure your parts before you start cutting.
For a mid-80s wiring diagram, go to our
Technical Pages. Of course, there's also
model-specific information in the Technical Pages, but they are large files - be patient while they download (1-3 minutes, apiece). Good luck with your project.