Noisy Action

[Clark A. Sprague]

Friends,  Today I was working on a Young Chang G-175 grand.  Totally
regulated, steamed, filed and dry ironed hammers.  Actually this was done
a couple of weeks ago, but today, I found out that somebody bought it,
and they are a recording studio.  We tried to tell them that this was not
the piano for them, but they liked the tone, the touch, and the price. 
The problem is that the action is noisy.
        I steamed the whippen cushions, and it quieted them, and nicely
removed the dents (at least for awhile, I hope).  But the back rail felt
is the real culprit.
        Please help me with the following:  The back 2+ inches of the
keys are beveled off to meet flush with the felt, of which there is 2 1/2
inches wide of the stuff.  How much width do you need back there?  If I
replaced it with fluffier stuff, how wide should it be?  The whole 2+
inches of the key end is plopping on the felt with a clunk.  HELP!  I
need to deal with it tomorrow.
Thanks a million in advance,
Clark Sprague, RPT