I do fancy do that. As you say, an extra piece of mind!I have a 98 300tdi. 175k.
Literally within two hours of buying it the oil light came on, and would thereafter come in once the engine was warm. A new switch was fitted and I've put 30k on it since, all good.
For piece of mind you can get a splitter at the switch connection to go to a pressure gauge in the cab.
Just turning the key causes me anxiety. There’s always somethingIts easy to think the worst. Great news