It was one I thought would probably be best forgetting about, but I felt the distinctive head and call combined were enough to work with. The notes I scribbled down about the super being sharply defined and ending infront of the bill match all my notes and photos of dusky from Asia, plus everything on a google search. Chiffchaffs' super is more diffuse and usually extends over the the bill, plus the call is completely different. Raddes', although never really thought of with this bird falls down on these features also.
Its good enough for me and I'm having it!
Chiffchaff from Tory Island, 2012, the diffuse super extending over the bill.
Raddes warbler, Beidehe 2010, just like the chiff, diffuse super continues over the bill.