You Could Be Right, But
why would the casino cater to farmers? I also think it is a 500 franc plaque, rather than 500,000 as we would read in English, and how many farmers would have that kind of money to gamble with? From that era the 1 franc silver coin was similar to our silver quarter so the value of the plaque was perhaps around $100 in the money of the day. That was good wages for a whole month back then.