FWIW,the base of the harmonic balancer is the iron counter weighted hub that is fixed by the keyway and the belt pulley is a light pressed steel ring riding on a thin rubber cushion fixed in place with rivets. When the rivets fail the steel ring will slip back and forth about 60 degrees on the hub hammering the assembly until it finally totally separates. If the balancer is removed before it is near destruction the outer ring can be turned to line up in its original position and a few tack welds made to keep it there. As far as balance goes the outer pulley ring can be removed and the engine can be run with just the counter weight on the crankshaft and there will be no imbalance problem.