First up is Conrad's full-on performance as an unsympathetic, swaggering creep that appears to be an unflattering portrait of himself. This was done shortly after his CBS series "The Wild Wild West" ended. Conrad was known for doing dangerous stunts and using his star power to influence the series. He and his stunt-men pals more or less dictated the direction of the show. Mitch Cantrell is a fearless star of a Western show/film (we see him shooting a scene), hangs out with his stunt-men buddies, and acts like he owns the studio. Cantrell, like Conrad, is also from Chicago -- which leads to our second point.
Cantrell often visits the "Chicago Street" on the fictional Majestic Studios (Paramount) lot because it reminds him of his hard-scrabble childhood. A key scene between him and Mannix has been unwisely trimmed down for syndication (recently by Heroes & Icons and probably other networks). The truncated version just shows Cantrell starting to talk about his past then abruptly ends with him staring at an alley across the way with no explanation. In the original uncut version he recalls being chased by a street gang and hiding in an alley, scared out of his wits. This was the turning point where he decided to rise above his fears to the point of being a reckless, selfish jerk. Without this dialog, his breakdown in the finale -- cowering in the alley -- comes out of nowhere and makes no sense. Too bad the need to shoehorn in more commercials gutted this episode, robbing it of any meaning. (Thanks, Heroes & Icons -- you suck.)