TC,
You may want to put the car up on some jack stands and do a thorough visual check to see if you can isolate the leak. It could be the rear seal, pan, or a number of other things. I'm no expert, but your
oil pressure at idle seems fine.
You might want to touch base with the original engine builder (was it CHP?) to see what they say. Even though it's not warranty, they should be helpful if they're concerned at all with word of mouth referrals.
Good meeting you at Alice's this weekend.
Doug