Thank you David and Paul, I understand now :-)
As you say David the Ghoster Halyard seemed somewhat superfluous, but being a man of almost no experience, I figured I would make it as drawn, in case I was missing something important... I will, as you say, try rigging it with 180-deg rotation and see how we get on...
David, I also remember liking the way you attached the sheet spans to the battens and sail, but failed to take a picture (or see it while we were in Brixham), do you have a picture/sketch/description you could share please....
Busily attempting to complete a "rigging warrant" - my we seem to need a lot of rope!