John,

Many of the cruise line's casinos operators back
then: Casinos Austria, Atlantic, Oceanic Leasure
and... had generic-type chips. Many of the vintage
ocean
liners I've sailed on during that era you mention;
via Miami (Btitanis; 1931 ship) never had their own
chips. I don't know if what you're looking for
exists with the ship's name on it. Many of the
cruise line chip collectors I know of
Internationally, simply enter any type of piece:
postcard, cup or whatever in order to help complete
their collections with at least representation.

JB