This episode marked the return of Ross Martin after his heart attack
Ross Martin is noticeably thinner in his first episode back from recuperating from his heart attack.
Patrice Munsel (Rosa Montebello) was a coloratura in real life. She sang at the Metropolitan Opera over 200 times.
The song that Jim West sings along to just before the fight scene it accompanies is called Lubly Fan, aka Buffalo Gals and was written in the first half of the 1800s. Its been in movies and TV shows, covered by Pete Seger and others. Its also covered live, by, "The Boss"