Update:
The car is back from being diagnosed at the Porsche shop nearby. Very nice folks. Dropped the oil pan and found this and didn't proceed any further. Oddly I didn't find any metal in the filter in the last 2 oil changes but they got some in the oil pan. All the bits they found are here (one green, a few brown, a few metal):
Car has 98,000 miles. They recommended a replacement engine of my choosing.
Dave