Found a selection of various ages at swedish photographer Lars Petersson's website:

http://www.larsfoto.se/sv/galleri/specialgallerier/aldersbestamning-av-jattehavsorn?res=1050

Shouldn't a 2nd c y be ruled out by the moult contrast in the remiges? Could a 4th c y be an option?

Probably 3rd cal. year, as primary moult has reached around mid-primaries, and about 505 of the secondaries have been renewed. This is too extensive for a 2nd cal. year and in line with 3rd cal. year; however, as usual, it is always difficult to select between a normal 3rd cal-year type and a retarded 4th cal. year. But the stage of moult etc. fits 3rd cal. year.

Approx. the same moult sequence as for White-tailed but here´s a specific paper on the subject for those who likemoult in pelagicus

JanJ