I found this stoneware bottle recently, and am perplexed as to it's value. It says (handwritten in the clay) "Levert & Co. Amsterdam. Anno 1690." on one side, and "federal law forbids sale or re-use of this bottle" on the other side. It's about 3 pounds and 12 inches tall. How can I tell if it was really made in 1690? How do i find out how much it's worth?