"Had exactly the same readings
"Had exactly the same readings on my 41 for one engine after the rebuild. They replaced the sender and I went to spec (65-70 I think).
The other engine was only just getting to 58-60,
and the low press alarm sounded after a run down to idle. Soooooooo because these senders are not cheap cleaned up the terminals and wires etc and the low P alarm went away. Decided to replace it anyways, and guess what pressure went up to spec like the other engine. PS these are made by Porche, so if you cross ref the books they are available as a after market, but the thead is taper instead of the straight on the Penta version. Good luck"