B = heel width
D = front width
in your instance, that's a standard run of the mill size (but those shoes should be Barrie lasted, which most size .5 down from their Brannock size)
I don't but wow, their site looks like it was made in the '90s:
I corresponded with them via email about size availability and then went in to buy from them in person. Had a nice chat with Voltaire the manager. Have you tried calling them?
Good experience. Would do business with them again.