The "hood" of Dr. Gritzky's machine is the clear Plexiglas shell and vented collar section from the head of the Robby the Robot prop from Forbidden Planet (1956). The Plexiglas here is opaque, probably on purpose so that when it is lifted, the sudden youth of Norman Swickert is revealed.
Maurice Evans and Bernard Fox both had acting parts in the 60's tv hit series "Bewitched". Maurice playing Samantha Stevens father and Bernard playing the wacked out Dr. Bombay.
The sets used as the interiors of Maurice Evans' mansion in this episode were also seen as the Nash family home in the TV series of Please Don't Eat the Daisies (1965).
This two-part episode was adapted from the novel, "A Bridge of Lions", and is the only episode to have been so derived.
This two part episode would later be turned into a movie entitled One of Our Spies Is Missing (1966).