It sounds as if the panel circuit board could have been ‘zapped’. This board is encapsulated with no way of repairing – it has surface mounted components and IC chips (experience from my 41 Classic) with the lamps moulded in.
To confirm the oil pressure, use a multi-meter and see when the oil pressure sender switch opens as you start the engine. If this is working then it is most likely the panel circuit board, which unfortunately is not a cheap replacement part.
Hope this helps and you get a satisfactory result (and not too expensive).