Once upon a time, southern Park Slope's Ansonia Clock Factory churned out timekeepers. In 1982, the German Romanesque Revival building was converted to co-ops called Ansonia Court while managing to maintain the beams, columns, and ceilings of the original. Don't confuse it with that other Ansonia on the Upper West Side; this one has 70 units surrounding a picturesque central courtyard. One of those unitsa two-bed, 1.5 bath duplexjust hit the market. Asking $1,575,000, there's also a private patio and a sizable lofted office space that "could be used as a play space, a home office or a cool sleeping loft."