Punches are available from pipe organ supply houses such as Organ
Supply Industries, Klann, Colby, Kimber-Allen.  (URLs available at my
web site.)

For very large punches used for making pouches, etc., we use steel or
cast iron water pipe that has been ground down to size and sharpened.
This requires some searching for old pipe of the right diameter, but it
does work.  The pipe does not remain as sharp as with a quality punch,
but it works on the small scale needed for repair work.  As a backing
block to punch against we use a large block of end-grain maple.  The
block can be cut or sanded when it gets too pitted.  Always use a
wooden or hard non-metallic mallet when working with punches, as they
can shatter from repeated blows from steel hammers.  Wear eye
protection too!

Pre-cut and pre-punched leather, felts, and other parts, can be
purchased from pipe organ supply companies, as the components are
standard items in the organ trade.

Regarding "Leather to Leather Gluing" -- Almost any good quality
flexible glue will work here.  High grade contact cements will hold
leather to leather forever under most conditions.  If you are using
leather for any work that has a coating on it (such as garment or coat
grade leathers) be sure to lightly sand the leather to ensure a good
bond with the glue.  Avoid using contact cement on surfaces that may
need to be redone in the future as the stuff is hard to remove.

For wood to wood joints that you don't ever want to come apart, we use
202 GF glue from Lee Valley Tools in Canada and the U.S.  See:

    http:/www.leevalley.com

This is also sold by Wade-Garret (?) and others, I believe.  202 GF
glue is a polyvinyl acetate resin glue "PVA".  Unlike most White and
Yellow glues that leave a messy glue line that you can never remove or
hide, 202 GAF glue leaves a dark brown squeeze-out line that can be
sanded away and it leaves no stains.  It does not soak into the wood so
you can scrape off any excess and have a perfect joint with no mess!!

It's a valuable and useful glue.  The cost?  For the largest bottle
(4 litres = 135 ounces)  $42.50 CDN (about $30.00 U.S.?).

Nelson E. Denton
R. A. Denton and Son, Pipe Organ Builders
Hamilton Ontario Canada
http://www.freeyellow.com/members/radentonson