It was smaller than an A before the blades were cut down. Compare the large OD against the register in the first pic(the register is 9.125). From the pic i would guess it started out as an A/B or a B. See how the small diameter and the large diameter have a little of the blade angle cut into them, berkeley used to cut their b's that way instead of just cutting the blade up to the hub on the small end and reducing the large diameter, it wouldnt look like that if it started as an A. I'd guess it was a B/C or a C now with the additional blade cut.