Whether you're on the hunt for a 1965 Ford Mustang or you already own a '65, it's important to know how your Mustang was originally built, when it rolled off the Ford assembly line. Should you be looking to buy an old Ford pony car, how the Mustang was originally equipped is a big key to establishing her value. Knowing this upfront can be used in negotiating a fair price, or deciding whether or not you wish to make an offer in the first place. If you're already a Mustang owner and you're restoring her to factory new, you'll need her DNA of how she was born (built) from back in the day.