Identity of Friday's Mystery Building Revealed

The most recent commenter, Will, is right: It turns out our mystery building on Friday is the Frederick A. Cook mansion on Bushwick and Willoughby Avenues in Bushwick. Thanks also to Matthew Rudert, a Massey Knakal broker specializing in the area, for being the first one to give us the heads up (via email). He sent us a link to the Forgotten NY page on Bushwick that laments the horrendous condition that this and other formerly grand mansions have fallen into. An interesting aside: Cook, an avid explorer, claimed to be the first person to reach the North Pole, but his detractors say this was just another of his many frauds (which included operating the first Ponzi scheme).
Bushwick Boastables [Forgotten NY]
The Man Who Inspired Enron [Peary & Henson Foundation]
CSI Brooklyn [Brownstoner]