In a scene that didn’t make the final cut of 1939’s Gone With the Wind, Rhett Butler sits alone in his bedroom, drinking and fondling a gun. A knock at his door interrupts him from his dark thoughts.

Silver Screen Collection/Getty Images Vivien Leigh (left) and Hattie McDaniel (right) appear in Gone with the Wind Historian David Vincent Kimel, who purchased a 301-page shooting script that once ...