I have a spare wheel for the 750 twin. It is from the CSR (M) model and the same as the B1 and B2.
It is different to the one in the picture. As you were previously advised the disc mount is 4 stud not 6. You will also need a disc either from a B model or M model. I have M model discs spare. What is the diameter of the 6 hole disc you have?
You might also need a caliper too but I have both types
