Further Update
Hi chaps,
we've been out on the Pan today for the first time with the mk11 2 piece bracket arrangement (as in post #16). I set the brackets in a position which was parallel to the moving brackets on the bike so the screen was at the same angle as stock, but with an increased offset of 1 1/2" from the 1" on the first set of brackets.
After covering one of our frequently ridden routes, which takes in open A roads as well as twisty back roads and speeds up to 100mph and 90mph cruising, I feel this position is a further improvement.
Neither of us encountered any real buffeting even at the speeds mentioned, although there was some noise, which felt strange without the buffeting.
Back pressure was only evident with the screen right up at the top.
I think i will alter the angle of the screen for my next ride out, then make up another set of one piece plates with either parallel holes or with the reduced angle if that helps any.
Stu