Save everything, right down to the screws.  Take lots of pictures.
Make sure the saved parts stay saved, not dumped.  Or save them
yourself for that piano.  There are three things that are significantly
different in a Steinway Duo-Art grand:

1. The fallboard may be attached on the ends by #4 wood screws through
a metal slide.  If the piano is butted up against a wall, you may have
difficulty getting a screw driver on the screws.

2. The "monkey" is not at the bass/tenor break but on the bass end.

3. The action shifter may be connected to the middle junction block
on the bottom of the key frame.  Either leave the part and remove
everything else or make the appropriate part.

As an aside, I find it difficult to believe that the cloth under
the piano significantly makes the piano quieter. If you could, make a
"before and after" test.  When it's all rebuilt, make note of how loud
it plays.  Put the cloth on and play it again.  Is there a definite
difference?  Let us know your results.

Jeff Davis
Seattle