From my searching of this thread, it seems that most take the same size on the 184 last. I just received my Westminsters on the 888 last in size UK 9.5E last week and they fit pretty well. They might be ever so slightly long, but the width seems pretty good. I'm comfortably in the middle hole for all buckles. I'm thinking I'll probably stick with a UK 9.5E for my upcoming order of a Piccadilly on the 184 last, but wanted to solicit advice from the forum. Any thoughts?