PROBLEM SOLVED!!!
My Sincere Thanks, go to both Carter and in particular to Karl, for your input and support in coming up with both
ideas and suggestions to resolve my problem.
After removing the battery again: -
I took the switch apart, just enough to stop anything flying off and gave it a good spray with a maintenance spray.
Then set about all the 'push in block connectors'. Taking each one I could find apart and giving them a spray before
reconnecting them.
Next I remembered the 'Relay' that Karl mentioned, it was just floating around under the front cover.
I found that the rubber retaining band had fallen apart, so I set about re-fixing the relay in place, using double sided tape and a cable tie.
I left this all for around 30 hours to thoroughly dry out.
Refitted the battery turned the key, pulled the left hand brake lever and the stop light came on and off hesitantly.
As a result of the above, I checked the 'earth' wire connection on the rear left hand side of scooter frame and noticed the nut would not fully tighten.
So I snapped off the welded stud, drilled out the remainder. Cleaned off the painted area and replaced the stud with a nut/bolt and spring washer.
Re-connected the battery and BINGO!!!
Stop light worked with a steady strong light and the starter motor fired up like it did when new.
Thank you both once again, for holding my hand through the trials and tribulations of this investigation.
(Its great when it all comes together!) Talking of which, I now have the laborious job of refitting all the body covers.
F. Keith A.