Another hooded Yellow-leg

So, I'm not quite sure what to make of this gull.  It's got yellow legs, a dark blue-grey mantle, not a lot of white in the wing tips, and a dark hood.  I guess its an extreme michahellis?  Or is it another atlantis type?

It was certainly striking when I picked it out of the melee on Stewartby tip this afternoon.  On an open wing shot I have it has a band on P5, and appears to have quite a bit of black still in the coverts making it a third-winter type.  My current best guess is a michahellis with an above average dark hood.  Any other suggestions?

EDIT - some more images of this bird can be found on my Flickr here.  These were taken Sunday morning in slightly better light.

Colour-ringed Gull

Shite image, but after all this time watching Yellow-legged Gulls at Broom, I've finally found a colour-ringed one! This one has a green ring with PCMW on its left leg, which makes it from the Ebro Delta in Spain, I think. I've sent the details away so hopefully we'll know a bit more about it very soon...