I suspect the oil pressure gauge in my 49 is off too. It's slow to register and doesn't show any deviation between idle and at speed. I know I'm getting good oil pressure to the valve train so I dunno.
I should put my very accurate oil pressure tester on it and see but I haven't gotten "round toit" yet LOL.

It's amazing these 60+ yr old engines and their components are still tick'n and still taking a lick'n .....

Dave