These are gorgeous coins. They come from the old Second Kingdom of France (1815 to 1847) and command good collector value today. Each coin contains 0.373 troy ounces of gold, so the base value (BV) is that number multiplied by the current price of gold. A the time of this writing, gold is trading at $1330 US dollars per troy ounce, so BV = 0.373 x 1330 = $496 US dollars.
Typical catalog values run like this:
average circulated: $700
well preserved: $1100
fully uncirculated: $2500
You can see that condition makes all the difference. There are some rare dates and mint marks:
1839A: $3000 in average circulated condition
1832B and 1833B: $1200 average circulated
1835L: $2000 average circulated
Joe was kind enough to include pictures of his specific 1837A coin. It is shown in our secondary picture (to the right, coins on diagonal, with shadows). Comparing Joe's coin to the almost uncirculated specimen in our primary picture, you can see substantial wear and some overall discoloration. This means Joe's coin is somewhere between worn and average circulated condition, giving a catalog value of $600 or so.