I face a similar issue but I think its worth asking is it the gauge or the appropriate sensor that is the issue?
my fuel gauge shows tends to show the same or similar reading, although it does move. However, the car has been stored for some time and the old fuel has a tendency to go to varnish and that in turn messes up the fuel sensor float mechanism. My gut tells me its more likely to be this than the gauge in the dash. so a good clean or replacement of the float sensor in the tank is my first port of call
similarly on the water temp, the sensor in the thermostat could be the issue and rather than pulling the dash apart I am looking at a new sensor that is on its way from barry thorne
I not David manners and others have new gauges for sale
