Former senator Margaret Chase Smith was at the National Portrait Gallery yesterday to see a portrait bust of herself by Mary Elizabeth Hart become part of the collection there. The Maine Republican served 33 years in Congress . . . Former National Gallery of Art curator Konrad Oberhuber, who has been curator of drawings at the Fogg and professor of fine arts at Harvard, will become the first Ian Woodner Curator of Drawings at the Harvard University Art Museums . . . Barbara Blum, former deputy administrator of the Environmental Protection Agency during the Carter administration and current president of the Women's National Bank, has been selected to monitor the national elections in Nicaragua Sunday . . . Women in Film and Video will premiere the Ann Skinner-produced film "Return of the Soldier" at a black-tie benefit at the K-B Fine Arts Theater in January. The stars of the film who are expected that night include Ann-Margret, Alan Bates, Julie Christie and Glenda Jackson. The benefit will help support the fourth annual Women in Film and Video festival at the American Film Institute in March . . . More than 12,000 fans attended a concert by Boy George and the Culture Club at the Louisiana State University Assembly Center in Baton Rouge in spite of hecklers waving Bibles and shouting, "God hates queers" . . .