The hammer won the day. I couldn't even push a fresh scalpel blade in between the two surfaces they are so smooth and flush. There are small rectangular blocks at the lead edges of the pan that are there for tapping on, I have since found out.

Thanks for the suggestions gents.

I'll post up some happy snaps after I change out the oil and I know whether it has made any difference.

So far so good as I haven't found any chunks of metal in the old oil and the gears that are visible look ok.

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Bye bye betty blue. Hello F6.