This is the first episode when the red gas pumps at Wally's were switched to a taller, gray model. The fact that they were just props, set up and taken away periodically, is reflected by the fact that the Regular and Super pumps occasionally swapped places from left to right, or had Regular on both of them, or had Regular on one side and Super on the other.
The character played by Jamie Farr is listed in the closing credits as "Grecos," but in the dialog both Murrillos and Andy refer to him by the name "Silvio."
Of the four "Gypsies" shown, none of the actors playing those characters were actual Gypsies (which was the norm in 1966). Two of the actors were of Italian descent (Vito Scotti and Francesca Bellini), one was from Argentina (Argentina Brunetti), and one (Jamie Farr, who played 'Klinger' on M*A*S*H), was Lebanese-American.
When Andy and Helen first meet the Gypsies, Helen says Mayberry hasn't gotten a drop of rain in 8 weeks.
Colin Male was the shows official announcer during its original broadcast days. His one on-screen performance was as the game warden in "Andy and Helen Have Their Day" from Season 5. In this episode he has an un-credited performance as the weather announcer on the shortwave radio.