brit car buff,
They are all the same diameter. Often, you can find this kind of thing out for yourself by doing something I have learned from being in "the biz" for quite some time.
Whenever some part may or may not interchange with another, I open up a catalog (or go to the online catalog) and look for some feature that might tie one thing to another. This is helpful sometimes to interchange wheel cylinders or other brake parts, or especially electrical stuff. You'll get the idea when I describe how you can answer your question:
What do the three wheels share? Oh yeah! They all are held on with knockoffs. Go to the pages of the three wheels & knockoffs and see what part number is on the plain two eared knockoff, and voila!, all three use the same part number. So it's a pretty safe bet they are all the same diameter, which they are indeed. Enjoy.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon