Hello mate.
The reason i think its the pipe is i took the pipe off the oil fitting, when i put it back on i got a dribble of oil come through where the braided hose meets the pipe union.
Ive heard that the oil pressure switch can be problematic but i didnt quite understand your description. There is a big 30mm block coming from the side of the engine with the oil feed attached at the end. So is the switch sitting on top of this block? What size spanner doi need for it?
Cheers,
Muffster.