Did you sort this?
I'm having similar issues and have a slight leak around the pump. Hoping this is the only cause of my oil pressure but it's dropping right down when warm to the point I can't do more than 5 miles
Using a built cosworth 2.5 with modified oil pump, cosworth baffle plate.
For last 18 months: 8 bar when cold, warmed is 5-6 bar driving and 3 bar idle.
Then suddenly last week: 5.5 bar cold, dropping rapidly with warming to 1 bar driving. No change of pressure with engine revs.
Taken from plug under alternator with electrical gauge, verified by a mechanical gauge.
Car has only ever used Silkolene Pro S 10w50 oil.