Gas gauge calibration unit

I remembered I had a tank sender from an 85 Omni. I did some tests with Ohm meter and was disappointed. The readings were random, from a 10 Ohms to meg Ohms. I could see the wire wound resistor, the slider, and hear the slider operate. I lifted the float several times, still gave flakey reading. I found my can of electrical contact cleaner, gave the sender a spray on the resistor and slider, it immediately started working. The resistance is about 7 Ohms full, 100 Ohms empty.

I located most parts to build a prototype. I plan to go to town tomorrow to pick up a few switches and LM317.