Trouble sourcing oil leak

hmmmm.....well I got the distributor out of the way and had a look at where the leak is coming from and it definitely appears to be where the sending unit should be. I say should be because in the threaded hole there was a 2 piece thing but was not the sender. I'm not sure how to describe it but it was a piece of metal that was threaded on both sides. The one piece threaded into the hole and there was a passageway through it and then a cap of sorts that screwed on top. Once I had a look it was obvious that this was not really supposed to be there. The metal for the "cap" was different (chrome?) and the thread pattern was far finer then the piece it screwed on to. No wonder it leaks!!

I knew the oil light didn't work but I assumed it was just a cut wire as half of the wires don't go to where they are supposed to!!

I suppose I could just thread a bolt into the hole but I would rather ensure the light works on the off chance I have oil issues at some point. Anyone know the part number for the sending unit (idiot light style not rallye).

Thanks in advance,
Dennis