Gull ID, Warwickshire (1 Viewer)

Hello all,
On Thursday I came across a large first-winter gull at my local lakes, which first caught my eye when I noticed the strikingly white uppertail and rump with just a small number of black markings on. Other features as well suggested to me that it might be a Yellow-legged Gull, but as I'm not fully confident with gull ID I'd very much appreciate others' thoughts please.
Photos below, including videograbs from these videos:
http://www.youtube.com/watch?v=YUouqnhJkQI
http://www.youtube.com/watch?v=42k-5raePrQ
http://www.youtube.com/watch?v=kcBxG2uu-EA
http://www.youtube.com/watch?v=IhzyJiNBlRc
http://www.youtube.com/watch?v=Pf7lFsnC7yk
Kind regards,
Matt

One more lot of videograbs showing one of the tertials with a white margin running along the entire visible length of the feather, perhaps of a different generation to the others? My main doubts with this gull lie with the tertial pattern and inner primaries.

And some photos from Tony Philp.