Someone asked a while back whether anyone sells kits with all the parts necessary to rebuild our petcocks on Honda CB350s and CB450s. I haven't found a kit, but I did get all the parts individually from my local Honda dealer. I'm guessing Honda used the same petcocks on a number of other bikes.
Total cost for the three gaskets was under $20
Here's a photo showing the parts and part numbers:
[img width= height=]http://i3.photobucket.com/albums/y93/waterlaw99/DSC05738.jpg[/img]