I own an EP 450 Z Minolta Copy Machine.  Parts for this machine are no
longer produced, but it is likely that the small part I need to repair
this machine is sitting in some copier service parts room in a bin,
waiting for a request.  The part is a rubber belt about 3-4" diameter
that turns the drum.  The unique nature of the belt is that there is a
smal section which is not rounded but is flat allowing it to grab a
certain part of the drum without slipping.  This copier is one of the
finest machines made, with enlargement and reduction features,
excellent lens quality and changeable trays for a variety of paper
sizes.  It has functioned flawlessly with regular service for 20
years, but when this belt finally wore out and broke, the service
company was unable to replace it as the parts are no longer made.  I
called a few other companies locally and most said the same thing.  I
suspect that this replacement part exists in some parts bin,
somewhere.  Find me this part and assuming it is exactly the right
piece, the "question" will be considered answered.  The part number
(referred to as an "O" ring) is either 1021-5306-03  or  1021-5601-01 
/  .  The photocopier world has changed so much in the past 10 years
that it will be a challenge to locate this part, but it is worth it to
me to put it out there for the treasure hunters among you.