Thanks guys. I wear a 10D in the Strand and McAllister and they are just the slightest bit too big. It does not cause any improper creasing or wear, just a bit of moving around in one foot for the first hour of the day. Living in Canada I can't try on any E widths without a major hassle, so I'm happy with what I have.
With what you both have said about it being a bit larger, plus the bit of extra room I already have, I think that going down to a 9.5 D would probably work out well. When I get them down the road I'll report back.
I wear 7.5E in the McAllister and they are just slightly on the snug side so when I got my Elgins (same last and leather as McTavish, I believe) I stayed with the same size. They certainly run larger and almost feel a little loose but I went with it because like I said my current McAllisters are slightly snug in that size. They feel almost like another width wider (EE). I got them from the outlets shipped to me so didn't try on a smaller size.