I have no personal interest, and I hope I'm not offending Rick 'n'em:

Whenever y'all want some sort of doodad, or a very good deal on things plastic, f'rinstance ball bearings for Harken cars (someting like $6 for 100 balls), or Teflon sheet for mast bearing chips, whatever...

(Information on materials is here, too)

http://www.mcmaster.com

Search engine is comprehensive. No minimum order. These guys have anything you want (including your valve, Gary.)