COME HITHER: Beleaguered model Maggie Rizer is back in fighting form after spending a couple of years slightly higher than show weight. Photographer Michael Thompson shot her in the nude for the fifth annual Viva Glam Casino invite. A source said the Alexander McQueen and Chanel couture pieces that were called in didn’t work for the Catherine de Medici concept that stylist Annaleise Estrada wanted, so Rizer decided to go without clothes. The June 15 event, benefitting DIFFA, was conceived by Rizer after her biological father, Kevin Rizer, passed away from AIDS, and it now boasts some new names on its host committee: Vogue’s Anna Wintour and Harper Bazaar’s Stephen Gan. Ironically, Rizer and lawyer Ed Hayes are suing her former stepfather, John Breen, for gambling away her modeling earnings.