As far as I know, the numbered ones are apparently bootlegs violating someone or another's patent claims (not sure if it was TSR's claims or someone else's, the details are hazy in my memory - maybe someone else can clarify...). I was lucky enough to score a couple of light purple and a swirly gray/black one with white numbers of that shape:
http://4.bp.blogspot.com/_rnxaNH0W0Mc/TGDpJRyIPCI/AAAAAAAAAgA/bbr5cbGY8oU/s1600/IMG_1347.JPG If you get some of those, hang onto them, because they're not allowed to be made anymore (for now at least...).
@omendawn - if you have some dice to trade, send me pics at justinmic@hotmail.com