Thanks John, i think that clears it up for me

Just to remove the last niggling doubt from my mind, RFC officers who transferred to the RAF will have their service record in AIR76, yes? So i don't really need to bother myself with WO339 at all? Hurrah for me if i don't - that'll save me quite a lot of time on the PRO website tonight getting the WO339 references!!
I've got a well-thumbed copy of "RAF Records in the PRO", which mentions ADM171 (for RNAS men), and WO329 and AIR1/1030-1033 for RFC and RAF men - you seem to know your way around the WW1 records at the PRO so i'm wondering if you'd be kind enough to advise if there's anywhere else ni can look for medal cards as well as the above references?
Many thanks in advance of any advice you can give,
Greg