Ms. Viola supervised every detail of the makeover. She went on worldwide shopping sprees to find precise shades of Venetian onyx (even the elevator is onyx) and other decorative finishes, and visited Versailles so that she could replicate its grandeur in her 900-square-foot dining room. She recently installed the finishing touches in the duplex library — a ceiling mural painted by an artist from County Cork, Ireland, and a two-story rendition of Kipling’s poem “If,” hand-stenciled by an artisan who has designed custom Christmas cards for the White House and the Vatican.
The grand staircase of Italian granite has a custom-carved mahogany banister, and many of the walls are decorated with gold-leaf filigree. There are service kitchenettes and powder rooms off both the parlor-level living room — which has a fireplace of Brazilian travertine, a coffered ceiling, a south-facing Juliet balcony, and a heated walnut floor with an inlaid stencil — and the third-floor banquet room, whose heated floor is black walnut with a marquetry border.