I'm a bit late to this, but maybe I can offer some perspective. I have these exact same shoes in the exact same last and size, and they fit fine. Admittedly, after 12 hours, they are a bit snug. The fact that they are not a closed throat probably helps. I have two other G&Gs, the St James in 10F in the TG73, and the Windsor monk in !0E in the MH71 last.
The St James was a bit snug when I first started wearing them, but have now, dare I say it, broken in, and fit quite well. I think that the construction allowed the 10E to fit me in the Arran.
For the Windsor, they were also a but snug when I first started wearing them, but they now fit quite well. It really helps to try them on, but since you can't in this case, I hope that his helps.