74 years ago this month, lovebirds Clark Gable and Carole Lombard were among the throngs of celebrities attending the world premiere of MGM’s Marie Antoinette at the  Carthay Circle Theater  in Hollywood (no longer standing, sadly.) The film has been on MGM’s drawing table for years; a pet project of producer Irving Thalberg, who died in 1936 before a camera ever rolled on the project. His wife, Norma Shearer, was set to be the star of the picture. After her husband’s death, the project was shelved while Norma grieved and was ill with pneumonia. The film finally started production in December 1937 and was a lavish affair, with a $1.8 million budget–practically unheard…