Equal parts charming and vintage, New York’s DUMBO (Down Under the Manhattan Bridge Overpass) neighborhood features a restored 1920s carousel, a plethora of art galleries nestled in historic buildings, an East River barge that now functions as a floating concert hall, and other off-the-beaten-path destinations. Located in a former tin-and-sheet-iron factory with a garden oasis at its core, 51 Jay Street is a collection of 74 luxury penthouses and condominiums built near old railroad tracks. The highlight of th…