Yes, that scene is marvelous from every angle. Another harbinger of things to come: Young Vito maintains Deadly Silence until Sr. Roberto comes down to his desired give-back, then he warmly shakes his hand, as if to say, "Gee, you're a warm-hearted guy." The stick, then the carrot. Never kick a man when he's down, as long as he did what you wanted.
DMC: It must have been a big joke on Brando's part. Since he wasn't in II, and refused to reappear for the flashback scene at the end, we can only conclude that he must have gotten back at FFC and Paramount by sneaking on the set when and locking the door when nobody was looking.