IDK if I read it in the Carlo book or Brotherhoods but I remember reading that Casso and Amuso met Mangano to travel for a sit down with Gigante under the cover of darkness. They travailed through a rat infested sewer to go to one of Gigante's walk-ups (I think it might've been his mistresses house). They were offered alcoholic beverages, and supposedly mob etiquette dictates that you refuse, but Amuso got loaded. Amuso was supposedly acting aggressive and banging his glass off the table while talking shop with Gigante, and Casso was giving Amuso shade in his retelling.

I thought it was a pretty hilarious anecdote that doesn't get talked about enough.

That Brotherhoods was some book. I must dig it out again.