I received these chips last December, on consignment, and before offering them for sale, I told the owner that I would do some research to ID this TR King, Large Crown, $1, gold tone Hot-Stamped chip in green for a "21 Club". In doing so, the chip did appear in ChipGuide, as a California card room chip, attributed to a "21 Club" with a location of Los Angeles, CA, but only because the complete set of chips was picked up at the Los Angeles TR King location. The ChipGuide entry has a comments that states the "21 Club" was located in El Cerrito, CA, but further research indicates otherwise, as follows...

A Google search leads to a US Supreme Court case (tax evasion) against the owner of a restaurant/bar in El Cerrito, CA with the name of "21 Club". In reading the details of the testimony of various witnesses in the case, the "21 Club" name was merely the name of the restaurant/bar, which had a backroom card room, called the "San Diego Social Club". The testimony also shows that the 21 Club (restaurant/bar) was opened in 1943 and the San Diego Social Club (card room) began operating, 9 months later, in 1944. However, both ceased operations in 1946, which predates the TR King record card date of 1947.

These "21 Club" chips were picked up by a Reddin Smith, for whom nothing is revealed in a Google search, on January 2, 1947. In addition to the green one dollar chips (in a quantity of 1,600), the order also included, 600 yellow 5's and 300 chocolate 25's chips, for a total of 2,500 chips. Therefore, the "21 CLUB" chips could not have been used at that back-room card room.

If anyone is interested in owning one of these imaged 10 chips, each is offered at $30, with free shipping to a US address. These chips are in nice, played condition, with strong gold-tone hot-stamps. They all stand on edge and actually have fairly sharp edges, with no warpage. If you want more than 1, we can discuss multiple quantity discounting.

Images show both sides of the 10 chips offered, and their on-edge view in a rack. Note the one example of a cleaned chip, is not being offered here. Must use feeless PayPal or Zelle.

Thanks for looking. Jim