Help! Wiring for Vintage auto meter tachometer

I have this vintage Auto Meter brand tachometer it has a 288 model on the face of it

It has 5 wires Black White Green Orange Blue

the black wire goes to a socket that has a light bulb the white and blue seem to have conatunity with a ohm meter the orange and green do not (to gorund)

I tired to call auto meter but no luck his thoughts where the orange turn to orange form old age.. and white goe to the light

But if you guys could help out I can install this

One last ? if the green is to the neg side of coil I am using a Ford duralast ign (electronic) can I use the coil or do I have to find a rtach wire on the electronic module box on the firewall ) thanks DANiel