Heavy touch & no dynamic range

[Newton Hunt]

First things first.  The touch weight/geometry problems have to be
resolved before considering the tone/volume.  The first effects the
second so profoundly (psych-physical effect) there is little point of
discussion until the first if fixed.  Fixing the first may very well
solve the second.

There is another possibility:

Cut saw kerfs on the back of the rail and force hardwood veneers into
the cuts this will force the rail to warp back where is should be.  I
would check the alignment of the support and action bolts first. 
Realigning those may well solve the problem the easier way.

I had a similar problem with an S&S L a few years ago.  A thread
showed the drop screws in the center off by more than 1/16".  I
plugged the old action screw holes, redrilled them in a straight line
from the ends and remounted the stack.  Problem solved, played like a
dream.  Happy customer.

I discover this problem when I tried to put weights on the keys to
determine what the up weight might be if the down weight was in the
ball park.  Key would not function because up weight was too light. 
Therefore there was a problem elsewhere and started to search.

Good luck.

		Newton