I put it all together again on the bench - actually on a table next to the car.
I connected the pin output to one side of a 100 ohm pot and grounded the other side
I also connected my DVM into the resistor circuit.
When the cluster was powered the DVM read 1. (open), so, I would sneak up on the adjustment and watch the gauge. Once the needle got where I wanted it and stopped moving, I powered the cluster off (removed ground), and read the ohms from the DVM.
Readings from the fuel gauge
E = 40
1/4 = 30
1/2 = 18
3/4 = 13
F = 11
I ran out of time but I will see about getting that to repeat later, maybe with a different pot.
I will also note the numbers from post #3 (74, 23, 10), adjust the pot to that resistance, then see where the gauge goes.