The bulky, bone-colored beak seems completely wrong for LBBG, or at least I have never seen one with such a bill pattern. How is GBBG completely eliminated?
I would post this on the NA gulls Facebook page
I could get on board with the rightmost group being all Tundra. The rightmost bird of the left group is definitely Trumpeter. The size difference is not always super noticable, particularly when considering perspective.
That well defined streaking is classic WWCR. Plus color and bill size (WWCR generally appear to have a slightly smaller bill, but I'm not weighing this heavily, it just contributes to the impression)