The number of prop rings made, as well as what happened to them, as quoted by the characters, actually mirrors the setup of Lord of the Rings as well. Howard claims that 9 prop rings were made (the 9 rings given to the race of Men), 3 were taken home by members of the cast (3 rings were given to the Elves), and the rest destroyed, leaving just this ring (the One Ring). In actuality, many more replicas were made over the course of shooting the films.
Sheldon's "ketchup" spiel was almost a word for word recitation of a portion of the "ketchup" entry on Wikipedia at the time, with the only difference being that a few other flavorings had been omitted.
Leonard finds a Ghostbusters II (1989) script in the box. Johnny Galecki starred in Bean (1997) with Ghostbusters II star Peter MacNicol.