David Fincher’s long-awaited biopic Mank, about Citizen Kane screenwriter Herman J. Mankiewicz and his bitter dispute with Orson Welles, wrapped filming earlier this year and is expected to debut on Netflix sometime this fall. The film stars Gary Oldman in the title role, and, interestingly, was written by Fincher’s father Jack. Amanda Seyfried co-stars as Hollywood legend Marion Davies, and Collider recently got a chance to speak with the actress about her upcoming horror film You Should Have Left, during which she revealed some details about her experience working with Fincher. [caption id="attachment_705963" align="alignright" …