I started with a much clearer head this morning.
It could be that the switch could be in any orientation because it rotates in the headlamp shell.
But a better orientation could be :-
The moulded OFF position facing forwards towards the FRONT of the bike,
The moulded terminal number 8 corresponding to the moulded OFF position.
Does this sound correct?
Many thanks.
ps the switch and the bike needs to be completely re-wired, which is why I want to cross check the wiring at every stage.
Dave