So I looked again like you suggested...
Oil was on the lh side of the oil pan and sump spacer all the way to under the side stand bracket
Nothing on the rear face.
I poked a cotton swab in the slot and just a little dirt was on it.
I am gonna change out the gaskets and hope for the best.
Funny... this bike has had a CARC leak (-thnx AF1), a leaky shaft seal, and now hopefully just a leaky oil pan gasket.
You would think it is british!