I'm intrigued. If I read the documents correctly, when they changed from fabric to metal elevators, they refitted the original balance weights. Also, there does not appear to be any individual balancing instruction - they merely put the balance weight in place, no actual measurement of the imbalance. Is this correct?
Sounds like the bobweight may have been acting as an additional balance weight as well. Hardly a case of distribution along the hinge line, but it may have helped.
Does anyone know what the actual balance requirements were?