You don't have an oil pressure problem if we can assume your oil level is fine. Consistent oil pressure is your friend. What you want to look out for is the enemy, which is the instance oil pressure drops suddenly.
At this rate I would think something is causing the needle to raise artificially higher than the actual value; at this point I wouldn't bother verifying that.
It simply wouldn't jump to maximum. Porsche designed the range of the needle to assess all possible values. Even with an extremely thick oil 5.5 bar is max.

Source: manual

 

I read that note in Clarks Garage last night and plan to check that this morning. Every day's a new mystery when restoring a Barn Find. Over the weekend I did finally finish replacing the ugly white seats with black to match the rest of the interior. Also the rear side panels over the speakers. The rear hatch had leaked for some time and ruined them. New hatch and seal, too. Making progress.