Photo 8: LBBG sub-adult, June 17 2001, Missouriweg Maasvlakte, the Netherlands. 

Probably a 5cy LBBG without primary tips and a small mirror on p10.

The primaries and the colouration of retained old brown hued coverts and tertials may advocate 4cy LBBG, but the extensive white trailing edge of the visible secondaries seem to be more in line with at least 5cy birds.
The blackish primaries have no white tips but there is a clear medium sized mirror on p10.
Some outer and the innermost greater coverts are old, bleached brown but most of the coverts, tertials and scapulars are grey adult-like feathers.
The bare parts are pretty adult-like, as seen in more sub-adults; yet with a faint black marking on the upper mandible.