Rupert Murdoch had one more blockbuster deal in him. And it might be the grizzled veteran’s sweetest yet. The 87-year-old mogul is poised to complete a $71 billion sale of selected 21st Century Fox Inc. assets to Walt Disney Co. While Murdoch’s track record is mixed -- the 2005 investment in MySpace was a half-billion dollars he never saw again -- this transaction will cement his legacy as one of the media world’s top wheeler-dealers. After competition from Comcast Corp. pushed Disney to...