The "patient hitmen with a bottle of brandy" story is found in the Carl Sifakis book, The Mafia Encyclopedia. That book also claims that Zwillman had earned Genovese's ire by backing Anastasia and Costello against Vito.
In the Luciano book, he claims that the Brooklyn guys (Gambino's people) did in Longy because he "put the arm on Carlo" for money to help with his IRS problems. Luciano was critical of Lanksy for not interceding.
Zwillman had recently been subpoenaed by the McClellan Committee and was found dead just before he was due to appear.
"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming
Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.
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