(5 images) LBBGE053, 2002-2003, Missouriweg, Maasvlakte, the Netherlands (51.59N,04.02E). 

LBBGE053 8cy, May 12 2002, Missouriweg, Maasvlakte, the Netherlands. 

A bird ringed June 01 1995. From the same nest as E052 and now breeding close to the place where it was ringed, just like it's sister E052.

LBBG E053 9cy, April 06 2003, Missouriweg, Maasvlakte, the Netherlands. 

Note the relatively small tips on the outermost primaries P9 and P10. There is some black on the upper mandible both in April 2003 and May 2002, and this individual E053 is moulting head feathers on the throat by April. Incredible as it may seem, E053 chooses the exact same small pit when returning in the colony (compare the top and bottom images!).

(below) LBBG E053 9cy, June 02 2003, Missouriweg, Maasvlakte, the Netherlands. 

E053 returned again to the exact same spot it occupied last year. It is in active head-moult, accentuating the red orbital ring. Interestingly, it has a clear yellow iris without speckling right, but extensive speckling in the left iris. E053 has some faint black on the upper mandible and the red gonydeal spot extends on the upper mandible.
It is probably a female (code V0). P10 has a large mirror. The complete moult hasn't started yet: P1 is still present by June 02 2003.