Once a string of dim rooms linked by a narrow, joyless corridor, this Fifth Avenue apartment was reborn in natural light. The new plan clears the clutter with a wider gallery bringing more light, better flow and a library with a life of mementos on display. In the living room, a wall of mirrors pulls in views of the park and stretches the space in a way that feels easy, not showy. It’s the kind of transformation that reminds you how a few clear moves can turn a tired apartment into a place that feels both open and personal.