The dates 1452 and 1519 are Leonardo's birth and death years, not the years of the coin. There is not a lot of definitive information about this souvenir or keepsake token, so it is difficult to accurately evaluate it. Two points:
1. It is modern, so it carries low value
2. If it is silver, it is worth its weight in silver
These sell on eBay along with many similar Da Vinci memorabilia for $5 to $20. There are different reverses which go with the same full-beard obverse (front side). In addition to the Mona Lisa pattern on our main picture, one popular reverse has a nude female and one has a 'concept of manned flight' motif, shown in our secondary pictures.
Some of these tokens, but not all, have the inscription Ag 999 1 oz (or similar inscription). 'Ag' is the chemical symbol for silver, so the legend indicates that the token contains one ounce of silver. But just because it says it, does not mean it delivers the goods. The example in our picture (from eBay) says 'Ag 999 1 oz' but it sure does not look like silver to me. I'd never pay full silver price for it unless I had it tested and weighed by a jeweler.