So..
Another awesome find.
Theres petrol on the tank, LHS. Its not the filler top, its not the rubber coupling on the filler neck, either of them, and its not the pump from what I can see under the seat panel.
This only leaves the joint connecting to the tank at the bottom of the filler neck right?
It looks a ****ing PITA to fix? All help appreciated. Surprises me how many cars go through dodgy MOTs..