That's why I was suggesting it is not an oil pressure problem per se, and that you should suspect the wiring!
Has dampness got into the cab over the winter?
Has the instrument pod been off lately?
etc?
Only if one (or other, high or low) goes off regularly under set conditions would I suspect the senders themselves, but you never know.
There are quite a few senders too, itemised in the Wiki by pressure, normal vehcile fitment and colour code and part number:-
DOPWS Pressure senders list