Hello Pete.
No one here I see.
Starting with ageing the gull. The second generation tertials, inner greater coverts, scapulars and pale underparts seems to belong to a 2cy - September - would mean a gull moulting to second winter.Structure, and bill shape doesn´t remind me of a Caspian Gull or a Yellow-legged, but it doe´s a Herring Gull, or perhaps a LBBG?
Due to the quality of the image it´s difficult to see the various characters such as pattern of coverts & scapulars, primary projection and moult score of primaries.
JanJ