The jumper across the two metal studs on the back of the rheostat is usually the best method. It does not modify the board, fixes the problem (you want as much brightness as possible anyway) and leaves things so you can replace the rheostat in future.
Something to remember, DO NOT put any torque on the oil line to the oil gauge unless you want a constant drip of oil into your driver's compartment. Use one wrench to stabilize the housing and another to gently loosen the oil line connector.
Also, don't start your car with the oil line disconnected.
All this is hindsight - I made all the mistakes and paid the price.
