Aliza Gur's 13-year on-screen career was laden with espionage vehicles. Besides this episode of Perry Mason, she was in the spy films From Russia with Love (1963), Night Train to Paris (1964), and Agent for H.A.R.M. (1966), as well as the TV shows The 'J' for Judas Affair (1967), Absorb the Greek (1969), and The Night of the Cossacks (1969).
Because of "stock footage" of Perry going into the "Los Angeles County Courthouse 1958," in terms of his cars, he has been "downgraded" from a 1965 Cadillac to a 1962 Ford Galaxie.
In this episode a portion of a "script" is shown, ostensibly written by Mr. Mason. The excerpt is noteworthy for several missing apostrophes (along with some used correctly), as well as the customary dots being replaced by circles in each lower case "i," the question marks, and the exclamation points. The printed words contain a mixture of capital & lower case letters. He should have let Della write it.