Geoff,
I'm interested in why you think this is owstoni. When I saw the pictures I assumed it was a first-summer male narcissina. It may just be my screen, but the upperparts look grey-brown rather than olive-green, the underparts do seem to have an orange tint (although I admit not as strong as typical narcissina) and the pattern of white on the wing looks typical for narcissina. I also thought the late date would favour narcissina.
Identification of first-summer males of these (sub)species is not straight-forward and the ID notes on the Birds Korea website highlight that owstoni is variable at this age. I wondered if there was some important ID features I might have missed on this bird.
