Anglo-American Romance-Miss Leslie Nast, 18-year-old daughter of the late Conde Nast, American publisher, and her fiancee, Lord St. Just (Peter George Grenfell), 26, are shown in London, Tuesday, after the announcement of their engagement. Miss Nast is the Stepdaugthter of Col. Rex Benson, former British military attache in Washington. Lord St. Just is the son of the late Edward Grenfell, the banker, who died in 1941. They plan to marry in April. January 27, 1949. (Photo by AP Wirephoto).