An update on this... I finally did what should have been obvious all along and contacted CX's GSA in Doha directly (contact details: http://www.cathaypacific.com/cpa/en_...ountryCode=QA). He is very responsive, and although initially unfamiliar with the Oneworld Explorer products he learned quickly. He was also happy (for me as a CX Diamond at least) to arrange everything in advance and then swipe my credit card on arrival at DOH on a same plane turnround. There was no question of an additional commission - just the published fare + taxes.

Unfortunately, due to me losing my passport at a crucial juncture I had to pull out of the arrangement at the last minute, and I am feeling somewhat guilty about that. So I would definitely recommend anyone looking for the best value AONE3 out of Europe/ME to contact Shiadh Abdul Rahman of Trans Orient Travel (CX's GSA) to see what he can do for you.