Mahogany millwork, plaster ceiling moldings, stained-glass windows: these are just a few of the stunning details to be found inside this historic Park Slope townhouse at 566 First Street. A restoration sought to restore as much of the limestone home–which was built in 1906–as possible, while at the same time integrating modern amenities from a dumbwaiter to audio and lighting systems. And now the 4,900-square-foot stunner is on the market for $5.475 million.