Bedding the Balancerail:
There are three principal styles of grand keyframe balancerail - the stiff, Steinway/Mason & Hamlin style supported by adjustable glidebolts, the more flexible Asian style with glidebolts plus hidden glidebolts for action elevation, and an awkward alternative with no glidebolts. In all three cases, the balancerail fit can be affected by any of the previous steps being off, so first steps first.