Hi Mike,  I will first write a plea: remove the action to restore the
piano but put it back.  A concert grand pianola is extremely rare --
much rarer than a regular concert grand piano and it should be saved
as a pianola.

I just had my Weber Duo-Art piano mechanism serviced and so the memory
of the pains of removing it is fresh in my mind.

First, lift up the cover that's in the front the piano (the whole cover,
not just the small box where the piano roll sits).  Assuming that it
has the same type of mechanism as my own, there is the following to
disconnect before being able to remove the top action:

1. on the bass side of the piano a bunch of control tubing, two wood
blocks screwed together.  The screws go up on both sides so look for
them -- they're hard to find but they're there.

2. the roll motor on the right side -- unscrew the 4 screws that attach
it to the wall of the piano.

3. two rods, one on each side, need to be unscrewed.  On the left
there was a screw (a nasty little thing that likes to jump out of the
mechanism as soon as it's possible, so watch it), on the right there
was a hook with a spring covering it to release the rod.  Then unscrew
the rod from the connecting source.

If I'm not mistaken, then you're done on the top, so it's now time to
attack the underside of the piano:

4. Remove the pedals; you can't get to the mechanism through them.

5. In front of the keys there's a small cover, and underneath it is
some brass levers -- you need to remove all those levers.  Unscrew them
and wiggle them free while giving opposite pressure to the rods they're
connected to.

6. On the treble side of the piano, towards the front of the keyboard
and underneath, there should be an unusually shaped pneumatic with two
long slotted arms that push on either side of a pole (coming down from
the rod marked play/rewind).  You will probably need to remove this to
get to the connections under the keyboard.

7. Screwed in to the underside of the action (from underneath the
piano) are 2 or 3 boards, depending on the age of the piano.  Each has
a screw about every 2 to 3 inches, on both sides.  Unscrew all those
screws (there are about 20,000 of them!).  Be careful because they like
to stay in place until they're right over your eyes.  :)

I think you are now ready to remove the piano action.  Do so extra
slowly and carefully as there are extra parts on top of it.

Removing the player mechanism now from the piano action itself isn't
hard but putting it back in place is a pain, though.  :)  Remove all
those tubes that go through the keyboard, remove the screws that screw
it in place above the keyboard and lift it out.

To ease on assembly, I think it's nice to save a guide: I remove all
the tubing except for a piece when it comes to a break.  On the breaks,
I leave the last piece and the first piece, and then I cut them off in
a way so that I know which is which.  (For example, one is cut closer
to the tracker bar, the second one is cut closer to the keybed.)

Hope that this helps,
Eli Shahar

P.S.: One last thing -- before removing the player mechanism from the
piano action, you need to disconnect the damper-pedal lever (assuming
it does have one, a concert grand may not).  This pneumatic screws
through a rod to a lever with a V shaped jack that raises the piano
hammers.