Bump. 3 years later...
Ummm Shannon, that stamp

is most definitely a Scott #500. Weiss, along with all the expert groups out there, because we are all human, made mistakes. If I were you, I'd send it in for another certificate if you still want it certified.
Or, if you still think it's a #499, I'd be more than happy to offer you 100 times the catalog value of #499 (which is 25 cents) for it.
