You can get individual delrin spur gears fromwww.smallparts.com
but if you know the pitch and size
you can find them on ebay and the web!
Gear companies like "PIC" and "W M Berg" may have
high minimum order requirements but you can find them on the web! Call them!
They may just send you samples to keep you happy!
I called a company last year for a enclosure for a
project and they asked me if I was a Ham and they sent me the $25 encloseure for free!