Also, originals had a fuel petcock (with reserve) under the dash.
My car is wired the same as Bob's, but with an "A" gauge-set. I had Harmut remove the gas gauge in the "combi" gauge and replace it with oil pressure. I've got a fuel light that lights up with a gallon or two left.
I never use it. I reset the trip odometer every time I fuel up, and just drive it for 200- 250 miles then fill again. Honestly, of all the useful gauges available for a vehicle with an engine as prone to problems as a leaned on T1, a fuel gauge just seems like a waste of valuable dashboard real estate to me. I've never missed it. There are any number of gauges WAY more pertinent to me-- oil pressure, cylinder head temperature, even an hour meter would be more useful.
That's my opinion, not necessarily the opinion of staff or management. Your mileage may vary.