Dont chance running it...! I am doing this from memory but If you look under the filter there will be a 2 pole sender. There are 2 wires on it a Blue/White which is your guage and a Blue/Red which is your warning light. If you short each one in turn to ground the light should go off and the guage should read 0. This will tell you if the sender is at fault.
I had a similar issue on my '44 and got a single pole oil warning light switch off a Golf (I think) at a local motor factors. I wired the light only Blue/Red. I had to wait a while until the proper sender came in.
Always assume that you have no oil pressure - As suggested earlier get a mechanical guage to prove that it is ok.
