I also have one for 12th anv.1998

See Dick S. Site at: http://cashcoinconnection.com/Casino/USA/CA/NativeAmerican/NAS.pdf
which shows 7 of the tokens from Grand Opening through 13th anv.
I think the GO shown is for the new casino in 2005.

See Greg's Chip Guide at: http://www.chipguide.com/cgi-bin/search/search.cgi?id=cahism
at bottom of page. CG16533 for the 1999 token

Also suggest you direct a question to tribal office or casino at:
http://www.sanmanuel.com/
to find out how many were issued etc.

Jim Noll R3123