This was a great scam taking place in New York City during the 1980s documented on the show Unsolved Mysteries. A drunk accomplice (played horribly by the actor in this clip) tells someone on a pay phone that he found these rare coins in a bank envelope with a doctor's name and phone number on it. The victim calls the "doctor". He tells him to give the drunk $100. He explains that there is a $1,000 reward for the coins and gives him his address. When the victim shows up at the doctor's address, the doorman explains to him that there is no doctor and 2,000 other fools have fallen victim to the same scam. The key is the victim's greed and the man on the other end of the phone sounding like a convincing doctor. There are several variations of this scam which is known as "the pigeon drop."