DIED. Gary Merrill, 74, square-jawed actor who appeared in more than 40 films as well as numerous plays and television shows; of lung cancer; in Falmouth, Me. Merrill was best known for his roles in Twelve O'Clock High in 1949 and All About Eve, which starred Bette Davis and won the Academy Award for Best Picture of 1950. Off the screen, his well-publicized, tumultuous marriage to Davis ended in divorce in 1960, after ten years.