Hi Ken,  First of all, congratulations and good luck!  It is an
ambitious project but taken step by step you can get the satisfaction
that you want.

I would like to caution you that there are several different makes
of player pianos and the majority of them are easily restored, but
some are very difficult.  Before you start, send me the number of the
eBay auction and I would be happy to check it to make sure it's an
easily restored system.  The most common player system is Standard or
Autopiano; they're easy to work on.  Another common one is Gulbransen;
they're extremely difficult to work on.  (Although they can be done
and the piano is great if you do it correctly, I just wouldn't tackle
one of them myself -- I'm too lazy!)

As for a source of supplies, for a one-time job you should plan on the
following: do a search for Player Piano Company in Wichita, Kansas, and
for Player-Care in New Jersey, run by John Tuttle.  They're both fair
and have about everything that you will need (assuming that everything
is inside).

 [ http://www.playerpianocompany.com/  Player Piano Company
 [ http://www.player-care.com/         Player-Care

Supplies you will need:

Hot hide glue crystals: 2 pounds is plenty, also for learning how to
work with it.

Pneumatic cloth of three different weights: 1 yard for heavy bellows
cloth (John Tuttle can also sell you less) for doing the exhausters and
reservoir); 1 yard medium weight cloth, used for the air-motor, motor
governor, pedal pneumatics; 2 yards light-weight pneumatic cloth.

Tubing: You will need to measure the internal diameter of the tubing
and try to get the length you need of all sizes.  Usually there are 3-4
different sizes:  Tracker bar tubing (you'll need a lot, but I don't have
a rule-of-thumb); slightly larger tubing for certain control lines;
medium size tubing that supplies the air-motor and motor governor and
supplies the pneumatics for the sustain pedal, etc.; large size tubing,
supplies the pneumatic stack.

Leather: There is a lot of dispute as to what leather is needed
to be replaced and what is fine to keep.  I always replace all the
leather.  Imagine walking down the street in a 90-year-old pair of
shoes and expecting them to be okay.  This is where things start to
get expensive.  It is true that most players will play if you do not
replace the leather (valves and pouches) unless one of them is broken.

I use three different types of leather (minimum) in a restoration:

The first is called packing leather; it is used as a gasket between
parts.  I recommend replacing this at all costs -- old gaskets do not
seal properly.

The second is called valve leather.  The easiest way to replace this is
to contact the suppliers and find one that will supply you with punched
valves that fit your piano.

The third is called pouch leather, a very thin membrane that pushes
the valves.  I don't know if any suppliers sell this cut to shape or
not, but it is used in discs that are slightly dipped to have travel.
This leather is first installed in place, then it is sealed by one of
many techniques.  I've been told by one person that they brush it with
egg-whites, several others use a silicon grease, some use a leather
treatment called Hydrophane.  Whatever you use, it needs to be sealed
and then coated with talcum powder.

Shellac is used to seal wood and glue wood to metal.  In the USA you
can buy it at your hardware store.

You may need to replace other parts, depending on the system, but they
are different for each player.

*Don't be discouraged by that list!*  It's well worth the effort.

Good Luck!  Subscribe to the MMD -- there are many experts out there
that can help you to solve all of your problems!

Best regards,
Eliyahu Shahar