I have heard conflicting things about these chips. I don't think that chips looking like them even appeared in the movie. As I recall, in the start of the movie during the credits there are some chips displayed, but they don't look like these ones. Anyway, here is part of my ad for them when I sold some on eBay many years ago:

"JAMES BOND "CASINO DE ISTHMUS CITY"
MINT, CASINO-QUALITY SET OF 6 GAMBLING
CHIPS DESIGNED FOR “LICENSE TO
KILL”(1989), STARING TIMOTHY
DALTON - -- OF RECENT MANUFACTURE.

These sets of 6 different Casino De Isthmus City chips
have been selling for outrageous prices, for example
for $102.50 at an April 1998 auction. They are sold
for similar high prices at antique shows and flea
markets despite the fact that the professional casino
supplier that made them for United Artists for
“License to Kill” in 1989 has continued to make them
for the 10 years since. Though not rare or valuable,
they are colorful, mint and interesting -- chips every
Bond fan and movie memorabilia collector will want
to keep and display. (Note: many dealers who sell these chips may
not be aware of their recent manufacture.)

These chips are casino quality and mint-condition in
every way. They are clay composition with center
inlays and professional colored edge spots. They are
1-9/16th inches in diameter, have good weight and
razor-sharp square edges. "

Robert