I know you guys love rare jdm parts etc. So ive dug out the manuals and ill give you a run down of some of the gadets fitted.
The guages are Omori meter items, read water temp, oil temp and oil pressure. The temp is tapped into the sump and the pressure is T'ed from the oem pressure switch location.
I have one of these wired into the ecu, It reads MPH, trip and you can time quarter miles on it. No idea why you would want one, doesnt look like they kind of car used for drag racing.
I have one of these techtoms on the steering column, it plugs into the obd2 diagnostics port and when the cars hot you can read water temp, volts, rpm, speed, ignition timing, map pressure etc.
I also have a shift light setup wired into a pivot box or something like that. Ill take some pics and work out how it works. Keep finding new things on this car, turns out it has fender braces under the front wings!