oil tank

I am in the process of replacing my oil tank. The car is a 74 911. The replacement tank I purchased is used and is from a 78 911. I have my old tank off the car and the tanks match exactly as best I can tell. The old tank appears to be copper while the newer tank appears to be steel. The 78 oil tank is in excellent shape.

My question involves the circular sensor on the side of the tank. It is held in place by six small nuts. While I have the tank out and the car apart, and even though it does not appear to be leaking, should I remove the sensor and put a new gasket between the tank and the sensor?

Has anyone ever considered putting some type of additional padding between the tank and the body? The old tank was leaking from a crack where one of the two mounting backets were attached. I was wondering if over time movement could have caused this damage. What about some type of rock guard on the front of the tank by the rear tire?

While this has been a great project so far without a hitch(knock on wood), I don't want to come this way again! Any suggestions?

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