A hammer assembly for a grand piano comprises a hammer, a hammer shank, a tubular lever interface, a moveable knuckle, and a moveable knuckle visual location system The novel hammer assembly allows for a direct lever relationship between hammer shank and knuckle without requirement of a forked end hammer shank with knuckle slot The moveable knuckle can be visually located onto tubular lever interface at anyone of multiple distinct locations along a range that runs parallel to the length of the hammer shank and the length of tubular lever interface The moveable knuckle visual location system allows for custom configuration of a specifically dimensioned hammer assembly with custom "tubular lever interface center-to center" dimension to refurbish any brand of grand piano from one stock-set of hammer assembly components.
