Oscar de la Renta's Sunroom, 1970Courtesy of House & Garden’s Complete Guide to INTERIOR DECORATION ©1970In an industry that thrives on superlatives and constant upheaval, Oscar de la Renta was unique. His design career spanned more than 50 years, with stints at Balenciaga, Lanvin and Balmain couture, and he headed up his eponymous line from 1966 until his death earlier this month. He was a bastion of immaculate style – emerging at the end of every show in a suit, tie and silk pocket handkerchief. His unabashedly beautif...