Here's something that might help readers.  Like others I have found
difficulty in the past in replacing leather belts.  One solution that
may help those who are not purist enough to insist on non-synthetic
materials is a product called "Polycord".  This is polyurethane belting
made by a Swiss firm called Habasit.  It's available here in Australia
and they also have a branch in the US.

The address is Habasit Belting, Inc., 3453 Pierce Drive, Chamblee,
Georgia 30341 USA.  I'm afraid I don't have phone or fax numbers.

Polycord comes in 2,3,4,5,6,7,8,10,12 and 15 mm diameter.  Unlike
rubber, and like leather, it has rather limited elasticity.  They say
about 3%.

However the wonderful thing about Polycord is its ability to be joined
by cutting to the required length, then holding it up to a heated iron
(i.e., an old clothes iron) for about 10-20 seconds (experiment will
show exactly how long).  When the Polycord is soft and melting, butt
the ends together for another twenty seconds or so.  Then smooth with
file sandpaper or finisher.  The joint is as strong as the belting.

This may sound like I've got shares in the Co., but no, it's just been a
godsend to me at times and saved a lot of time searching for rubber and
leather belts of the size required.  Note.  Because of its lower
elasticity than rubber I've found it can't be used to replace rubber
belts used on small radius pulleys.

Bob Klepner
Melbourne Australia