Cooper S and Reverse Rim, the difference?

[minimatt1967]

Having just had a mini(ta boom-tisch) clear out of the garage, I have found some 4.5x10 ventilated steel wheels.

How do you tell if they're Cooper 'S' wheels or the reverse rim variety?

Many thanks.

[guru_1071]

the flat bit on a 4.5 cooper wheel is about 1"

on a reversed wheel is about 1 1/2 from memory