Oil pressure light

Evening all,

I am experiencing issues with the oil pressure light which keeps coming on despite the oil level being fine.

It usually comes on once the car is warm and the revs are up (no rev counter on this model)

It's a 1989 VW coupe 1043cc. I am in the process of changing the camshaft oil seal, timing end, as it is leaking. I am changing the oil and filter as I put 10w/40 instead of 15w/40 (thought the later manual would be the same! bought the earlier version now) and also changing the sump gasket as it's seeping as well!!

There looks to be 2 sensors on the cylinder head which Haynes doesn't go into specifics about and I've cleaned the contacts. I removed the wires to the sensors, but the oil pressure light and sounder came back on and the engine is making a slight pinking noise.

I bought a new pressure sensor and then realized I might need 2. 

My plan is to change the camshaft seal, change the oil, filter and sump gasket before I recheck the sensor and or change one of them out.

Any other things I can look to rule out?

Thank you