I bought a French Revolution era 5 Franc coin out of a box of other big silver coins that were at silver spot price + 10%. The only date was "l'an 7" which I knew would put it in the Directory period (it dates to September 1798- September 1799). There is supposed to be 9 or so variations, but I wasn't able to definitively place this in any of them. Hopefully someone here can help with which one it is, and maybe its value.
Your date is correct, the "K" denotes it was struck at the Bordeaux Mint with a mintage of 64,000, the catalog values are VG $40, F $100, VF $250. There are 7 variations that I can see ,yours is KM#639.5
Neither. You "keep" it all the rest of your days, the first (I assume) big find you ever made, and a wonderful testament to the fragility of most revolutions, including Crimea, for instance. My guess is that its value in inflation-adjusted dollars has been pretty stable for decades, although many slicks have probably been melted. If you need a couple of "gotta-have" coins to finish a set, I suppose there's nothing wrong with selling the coin, but doubt if you'll ever find another. I have an 1803 Russian crown (worth much less, however) from much the same circumstances, for sale on CT, see it here: http://www.cointalk.com/threads/russia-1803-silver-ruble-craig-125-65-postpaid.244012/
