A modern-day Rat Pack comprising Brett Ratner, Brian Grazer and Graydon Carter is in talks to team up on an HBO doc based on “Mr. S: My Life with Frank Sinatra” by Ol’ Blue Eyes’ longtime valet George Jacobs, sources tell us. The project was once slated as a feature for Ratner to direct, starring Chris Tucker, but has now been reimagined as a TV doc, insiders said. However, others and an HBO rep said no deal is done with the cable network. The book by Jacobs and Hollywood biographer William Stadiem was published in 2003 as a behind-the-scenes look at Sinatra and the original Rat Pack of Dean Martin, Sammy Davis Jr. and Peter Lawford, and included further anecdotes about Marilyn Monroe, Greta Garbo, Ava Gardner, Mia Farrow, Elvis Presley, Marlene Dietrich and the Kennedy family. Jacobs worked for Sinatra for 13 years, till 1968. Ratner’s produced docs on Woody Allen and ’70s star John Cazale, while Grazer’s currently producing Jay-Z doc “Made in America.” Carter produced the Robert Evans story “The Kid Stays in the Picture.”