I just picked up some of these chips -- four designs. All are neat unusual designs except for the concentric (at the lower right), which is pretty dingy. (Incidentally, you can have one of those lower-right concentrics for $8 total PayPal, just to have an ivory scrimshawed chip.) Anyone know why a poker chip would have a double-zero or double-O on it? Does it refer to a faro or gambling term or poker term? Someone's initials? Double-zero roulette wheel?

Robert
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Tim Holt (3rd left) and Richard Martin (2nd left) in "Trail Guide" (1952).
http://www.antiquegamblingchips.com/movie/movTim091514.jpg