Stavka, I'm going to guess that you're referring to Joe (the Boss) Masseria, even though I can't seem to make a connection betwen the name of the restaurant (Scarpato's) and "Tammoro's New Place." The identity of the three assassins jumps around, but I think there's a consensus on Benny Siegel, Joe Adonis and Albert Anastasia. I've also read accounts that put Vito Genovese and/or Abraham (Bo) Weinberg in place of Adonis and/or Anastasia.
I won't post another Q until I hear from you.