The WMK chips have denoms on them.

Nevada State Gaming Control Board, the investigative division of the Nevada Gaming Commission did not come into being until mid 1955. You can read the minutes of 1st 5 years of meetings here.
http://illegals.marlowcasinochips.com/other.htm
There was no internet back in those days and some people slipped thru the cracks. The main background check was done on NV records only.

The copies we had made were donated to the Club after we uploaded them.