Ah, Yes!  I remember the "Sting" -- never was there a piano
so aptly named!

These late Aeolian players have a great deal more problems with their
design than inferior cloth.  First of all, they use a Stack which is
designed to strike the piano action under the whippen, which is the
method most player actions employ.  This stack is then mounted so it
strikes under the keybed.  The mechanical advantage is all wrong and
makes for a hard pumping weaker playing action from the get-go.

The best design for this kind of under-the-keybed action, is a
teeter-totter type, where the pneumatic has a wider span and the lifter
finger is on the hinge end, like a Baldwin.

Another problem is in the valves.  In the late models I have seen the
valve consists of a sponge punching fastened to a wooden X stem by a
blob of contact cement.  Over the years the bond breaks and the valve
is just sitting on the seat.  When the instrument is jarred or moved
the valve slides away, and then you have leaks galore.

Sponge rubber valve facings, though they may seat well, are not the
best material.  They flex too much and this tends to effect the
response and repetition.

Lastly, the wood and other materials in this type of stack are quite
inferior.  The pneumatics will come off in splinters and the plastic
valve blocks will have to be sawed loose from the trunk lines, as any
other way is likely to damage these lines.  These are all equipped with
a suction box which, despite the noise, covers over these multitudes of
sins, so restoring the original stack wouldn't be totally out of the
question.

However, my advice here would be to make a new stack with proper
design, completely serviceable, with _no_ plastic.

Regards

Brian Thornton - Short Mountain Music Works
Woodbury, Tennessee
http://www.shortmountainmusic.com/