Steve Kroft of CBS' "60 Minutes" has paid $2,700,000 for a six-room co-op unit on Manhattan's Upper West Side.  The New York Post's fine celebrity real estate columnist Braden Keil broke the story this morning of Kroft's purchase of the 12th-floor unit, which is on the top floor of the building at 316 West 79th Street in Manhattan. The purchase was just recorded yesterday morning, according to public records. The two-bedroom co-op unit has two baths, a maid's room and a wood-burning fireplace, according to listing information. The unit had been listed for $2,900,000. Built in 1910, the building has been known over the years as the Kelmscott Apartments. Kroft and his wife, journalist/author Jennet Conant, previously had been renting in the Apthorp building, Keil reported. Check out an online listing sheet -- complete with a photo -- for the unit that Kroft just purchased.