Though not my sale; the 2½ Dollars which is seen on US gold coinage at the time... and which was preferred over paper currency out West, is what's engraved on the chip removing all doubt... especially since the "one unit" of the series follows the pattern as to what was commonplace at the time with Ivory gambling chips when an actual "1" wasn't use.

I'm glad I have both chips from the series in my collection.