Actually, all the indications are that the car is using NO GAS and it's a HOT car!
I have jokingly talked about rigging up those gauges to potentiometers to "dial-in" whatever I want on them. Otherwise it might be possible to connect them to something else. For example, have the gas gauge connected to a volt-meter so that the gas gauge shows the relative capacity of the battery pack.
I also measured the frame around the two side gauges, and they are just a little bit too small to remove them and replace with standard 2" volt and amp meters.