Really quickly before I get too deep into this a short lesson in the usage of penny versus cent. The United States of America does not have a penny as a measure of money. The penny is the measure use to describe a hundredth of a British pound. The only countries to use that measurement are on the pound. The cent is the measurement for the dollar and the United States uses the dollar, thus all the coins we have worth one hundredth of a dollar are cents. Now this isn’t a big deal in everyday conversation, but when you are a major news source you ought to be getting the nomenclature correct. Okay, that is all done on to the coin.
In 1792, when the mint was first setting up operations they did some trial minting of pieces to show how they could produce coins and the quality of production they could achieve for those in the government. They were also producing different experimental pieces to show what could be done with the materials they had available. The law at the time stipulated a cent contain one cent worth of copper, which would be 11 pennyweights (or half an ounce) which would make the coin larger than a Kennedy half today. To keep the size down the chief coiner also made cents with a silver plug in the center worth 1/4 of a cent. These coins were then delivered to President Washington for his consideration along with the full size cents. Very few of these were made, making them important historically and numismatically. That is why they trade for so much when they appear at auction. You can read more extensively about the history of these coins at http://www.ha.com.