Funny that this post came up, as I just broke my " Craftsman Industrial grinder" a couple of days ago. I knocked it over by acident and broke the bell off the motor.
Mine (was) probably 15 yeas old and has been an excellent tool. Well balanced and powerful.
It had a 7.7 amp motor. The closest thing I can find to replace it is an 8" Metabo on Amazon for about $250. Most other grinders seem to be in the three to four amp range.
Sears still lists some parts for the unit, but unfortunately the motor housing bell is not one of them. It looks like it is an aluminum-zink die casting so if I can't figure out how to jin up a repair, mine may have to be recycled.