Time spent researching and identifying the coin: approx. 1 hour. I initially focused on the reverse (back) —> IN … later it turned out that these are the initials of Napoleon's younger brother (HN), but based on the "style" I could already date the coin to the 19th century.
Research is the be-all and end-all of our hobby. I have a coin fragment here at v tector; the research took a little over a year. I looked through all the silver coins that were generally common here, and then everything fit together perfectly.