The six units that make up Tribeca Townhomes struggled when they first came to market, sticking out like a steel and glass thumb among the historic buildings of Tribeca. One of them is still struggling: the penthouse, which first hit the market in March 2008 for $9.175 million. The price was all the way down to $6.45 million when the 3BR, 3.5BA, 3,381-square-foot penthouse came off the market in January 2010. Now, a new year, a new listing! The apartment has the same price tag but a new broker. Will that finally do the trick? Remember, the exterior's not visible from any of the penthouse's three floors.