Justin Pitt was Elaine Benes’s eccentric boss at Doubleday on “Seinfeld.’’ His reason for hiring Elaine? She reminded him of Jackie Onassis. His assignments for her: finding the perfect pair of socks, taking the salt out off his pretzels, and making sure he would be able to hold a rope for the Woody Woodpecker balloon in the Macy’s Thanksgiving Day parade. Elaine once had to pry him away from the hypnotic trance of a “Magic Eye’’ image. Elaine was even briefly in Mr. Pitt’s will before it appeared she and Jerry were conspiring to kill him.