Often "ivory" on boxes like those refer to ivory COLOR. Probably not ivory, but to know for sure, you have to study the grain. This page might help:
http://www.antiquegamblingchips.com/distinguish_iv_bon_cel.htm
Robert
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BUSTER KEATON and ROSCOE "FATTY" ARBUCKLE in a candid gag photo of a dice game full of tension. They are being observed by SYBIL SEALEY. ... According to an attached paper snipe this took place on the METRO lot. VINTAGE ORIGINAL 8X10 GLOSSY.
http://www.antiquegamblingchips.com/StillsA_TopMaleStars.htm#comedians