cleaner to clean any chips, even actual brass-core chips because the cleaners I am familiar with are gritty, which is why they polish.

I do not know whether or not that chip is an error. It is peculiar in that the California Card Room offered poker, not blackjack, unless there was some backroom action going on.

Now that there is a picture of the chip, I suspect a California knowledgible collector will provide more information.

Jim