Yeah, that's what seems so odd. I'm going to wait and see what G&G say. I assume they can get to the bottom of it knowing the seller, seeing the info on the tongue, and seeing the box....I hope at least. The other funny thing is that 8.5 UK shoe trees seem to fill the shoe. When I put them side by side, they're about the same length and when I put the tree in, and feel the shoe, it is being filled up (at least through the vamp, hard to tell over the toe cap since I don't want to apply too much pressure there and ruin it).It's most likely that the shoes are a UK 9E as noted on the tongue of the shoe. I'm not aware of G&G marking anything other than UK sizing on the tongues of shoes. It's odd that the trees are 8.5 b/c I know G&G make trees in every half size, so there should be a 9UK tree which should have been used. Likely there was some confusion with WB marking US sizes on their labels, their system using the 'standard' UK 1 full size down on the printed labels as well (size 8), and then G&G being a brand that actually goes 1/2 size difference between US and UK messing it all up.
To further complicate your future decisions, if you are an 8 UK in other brands where they run a full size down to US (eg you are a true US 9D) then I'd venture this 9E could end up being too big for you once it's broken in because it's really closer to a US 9.5
If it is confirmed that it is indeed a 9 UK, then I'm more inclined to think that some of the extra room is due to it being a half size too big, and that it might be too big in the long-run as my foot sinks in. As you noted, I tend to be a true 8 UK in most shoes, and even then there's sometimes too much volume in shoes for me. But it's in G&G's hands now to confirm now.
I appreciate everyone's help on this.