If you are interested in Codes, try "The Code Breakers" by David Kahn. ISBN 0-684-83130-9. Kahn mentions the Thomas Jefferson Beale story on page 771. According to some of the Treasure Hunting magazines (my living in dreams hobby), there are also thoughts that the treasure has been found. Kahn also goes into the code breaking that was going on, prior to the Pearl Harbor attack.
It's good stuff lads, so if you want a good read, give it a try.
Regards, Max.
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When I push the panic button, the breaker pops!