Help Me Calibrate My Fuel Gauge

I managed to get my fuel gauge, sending unit, and bench power source hooked up and working tonight. I compared my original sending unit to a newer unit that was supposedly made by the original manufacturer.
My original sending unit needed only minor adjustments of the endpoints to "dial" it in. The repro unit did not respond in a linear fashion and really would not be useable. Looks like more wasted money on a poorly produced repro part.