My 69 Laurentian had the warning lamp group that included the "Low Fuel" light. It's a fairly cool feature - when fuel gets very low, the light comes on dimly. It then glows more and more brightly as fuel gets lower and lower.
There appears to be a little circuit on the back of the cluster that accomplishes this.
But thinking about it, since the fuel sender goes from 90 to 0 ohms, seems like you could almost just ground a bulb through the fuel level sender wire and it'd work. But that'd be sending a full unrestricted 12V into your fuel tank, so I doubt it works that way!
