Judging by the fact that a current can be detected running to the oil sender when the ignition is on, I guess it is the sender and not the bulb that is knackered.
Question is, does the sender usually have a take off point for oil pressure meters, or is this a replacement sender that came with the pressure guage that fitted ?
And what usually causes the sender to fail ? if I just take it out and soak it in white spirit, might that be all it needs ?