Instant gasket, remains of the baffle plate or old gasket.
1/2 a point to you sir! It is indeed what's left of the plastic baffle after my engine ate it. The pick up was so clogged you couldn't even suck through it!!!!!!!
I don't understand how it could have come off as I spent ages making sure it was fitted properly the other month when I pulled the sump off for the paint in the strainer issue.
Anyhoo Mark has taken my sump away to weld some proper steel baffles in it and I shall be picking up a windage tray and Derv Gasket this week. Will reassemble, fully engine flush, refill with oil and see if it's OK.
Nick