Nice piece of history you have there my friend. Here's a possible theory on the US coin:
The black market however, was a different story. Dealers in cash in foreign countries, France for instance, dealers were paying GI's 3 French dollars (equivelant) for each English dollar, and 4 French dollars for every American dollar. Europeans were all afraid of inflation and their only protection at that time was to convert their money for American or English cash.
Some GI's in the right position have made $3000.00 or $4, 000.00 foreign cash, on a payday.
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