I have a pretty cool 1600s Louis XIII double tournois. I can't seem to make out the date because of the corrosion (verdigris?). Any date guesses or tips on restoring? The coin will be going into my son's album...he gets all the cool old stuff.
I can see a 1 (161x) and it looks like it might be the infant bust from Bordeaux (K mm). So you have a choice between 1610-4. I'm guessing 1613 or 1615. If it's the he Juvenile Bust type, it could be 1617-9.
That's a cross at 12:00. You can see the 1 just above and to the left of the top left Fleur de Lis. The last digit in the date is between that and the Cross
Some of that looks like active bronze disease! Does any of it come of as a powdery type substance when you scrape it with a fingernail? If so, remove what you can with something like a toothpick/toothbrush. Soak in distilled water for a day or two and repeat scraping and soak again with fresh water until nothing else comes off. Dry thoroughly. I bake mine in the oven for 20 minutes at 120 F. Watch it....this stuff tends to come back. If you can get some verdicare as theodosius mentions, apply that afterwards.