Can you tell me anything about a Cuban Gold Commemorative coin, which reads 1856-1857 Congreso Constituyente on the back, and Primer Centenario De La Constitucion De 1857 on the front?

EDITOR: Thank you for the email regarding the Gold Commemorative. Actually, it is a Mexican coin. There is not much information on the coin in the reference books, but I think I have discovered what you are looking for. It is gold, .9 in purity. It weighs 41.6666 grams, or 1.2 ounces. They were minted in 1957 to commemorate 1857 Constitution. The Krause World Coin Catalog of World Coins lists the coin in the Medallic Gold Coinage Section, as KM # 122a. It also estimates the value as $2150 in bright uncirculated (BU) condition. I found 2 examples on the internet, with prices from $2000 to $5600. The latter was packaged in 1957 (anniversary) in a beautiful satin box, and was in BU condition.