Low oil pressure makes me nervous

Cool, and tnx. I have never seen an actual minimum pressure spec. That is good info!

Of course, what they don't say is temperature conditions for this test, but one would expect it is at average operating temperature, warmed up.

This also confirms, that if your gauge is accurate (which is totally questionable at this point) and your interpretation of the marks is close, then your pump is worn, or perhaps there is a lot of bearing wear.