(2 images) Larus fuscus fuscus 2cy, July 12 2003, Tampere, Finland (61.33N 24.59E).

This 2cy fuscus shows very barred second generation wing-coverts, especially the inner greater coverts, but in all other respects it is very typical 2cy fuscus in Finland in July. The visible primaries, P4-P10 are second generation, but the inner three primaries were not checked. The primaries were moulted on the wintering grounds. The upper scapulars are third generation already, rather brown but lacking any obvious barring or patterns, except the dark shaft-streak. The most recently replaced scapulars appear darker grey, not brown. Two lower lesser coverts and two median coverts have been replaced recently as well, probably third generation feathers and the dark coverts stand out in the otherwise barred wing-covert panel.
For another 'barred individual', check this link.

This is an example of typical Finnish fuscus, representing average 2cy fuscus in completely replaced primaries, rectrices and secondaries on the wintering grounds, prior to northbound migration. The new second generation primaries are only a couple of months old and still look dark blackish. The second generation tail-feathers normally still show the white tips, but in some individuals these tips are worn away when 2cy birds arrive back in Scandinavia. Immediately after returning in Scandinavia some 2cy fuscus start a new moult cycle in the inner primaries, now growing in third generation feathers. 
The complete moult in the winter quarters normally start with replacement of the scapulars and mantle-feathers. The new scapulars often show a simple pattern of a black shaft-streak on a dark brown base. The post-juvenile moult may already start in juvenile birds which are still in Scandinavia in September. When most of the scapulars are replaced, fuscus start to replace the wing-coverts, in the ordinary sequence that can also be found in other gull taxa in Europe. Wing-covert moult is initiated in two loci, one wave starts in the outermost coverts, one wave starts in the innermost coverts. The two waves normally meet at covert #7-8. Normally the median covert row is the first row which is moulted, followed by the lower lesser coverts, the greater coverts and moult finishes in the outer lesser coverts (the carpal edge). If for whatever reason, moult in the wing-coverts is arrested, this is normally most obvious in the carpal edge, containing juvenile feathers which contrast with the other fresh coverts. 
In classical 2cy fuscus, all wing-coverts are replaced to second generation on the wintering grounds, and by mid July, a next moult wave is initiated, often including the median and lower lesser coverts, the inner greater coverts, upper tertials and scapulars. Bare part coloration may be very immature, including a black bill, but may also be very mature, with a yellow base and a red gonydeal spot on the lower mandible. Still, these birds are only 12 months old.