Quite a few of the pre-war trikes had Brooklands wheels. They were of course the 17-inch wheels. Thicker drivers had trouble getting into the cockpit and several of these wheels had an arc cut from the bottom to allow the driver to slide in more easily.
If you can fit under a 15.5" wheel you should go for it. I use Brooklands wheels (17")for my Plus 4s, except for autocrossing, when I bolt on a 14" Astari wheel from a Plus 8.
