Firstly, thanks all for the help. I obviously last looked before David et al responded. I have now managed to get the screen working.
I found the header and all was fine, it turned out to be corrosion in the 12v crimp of the blue video module connector. With a pin in the connector front and another in the wire to the back of the connector I had no continuity.
I took it apart, cleaned up the joint, put back together hey presto it’s back up and running!!
Just need to sort out another NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- leak now from the shark Fin. But at least with the screen now working I have been able to confirm the shark fin is US. Now I just need to find a replacement!