Had auntie Mame owned this Manhattan triplex on the river, and had she been having - courtesy of that rich and charming Southern husband — a Venetian-palazzo moment, she'd have done exactly this. This stylish, sumptuous, drop-dead-glamorous flat. So Mame. Not to mention so Bill Sofield, who confides that its owners, a young couple with two small children, permitted him endless flights of Mame-ish fancy here. 'But I'm lucky,' he adds. 'I seem to find the most amazing clients.