Mike, NuTone, as well as the German hammers, can be ordered to be
exact copies of the originals.  Your tech will probably send samples
of each section to have them copied.  They will come back with the
proper shank-to-strike point length, as well as the proper tail length
and shape.

Hammer shanks come extra long.  The extra length is sawn off after the
hammers are glued on.  The trick is to get the hammers perpendicular to
the shanks, perpendicular to the strings, and hitting on the optimum
point on the string.

Play it for a month or two to see where the tone will go.  Then voice
if necessary.

The weight of an action is affected by friction, action alignment, as
well as the weight of the various parts.  Remember, a piano action is
a series of levers.  If, after doing a good job of regulating, the
action is still heavy, your tech can remove some wood from the hammer.
There is more wood there than is needed for strength.  Removing a
little at the hammer makes a big difference at the key end.

Jeff Davis, Seattle