"The Rifleman"'s producers must have thought highly of John Anderson, because he appears in 11 episodes, more than two episodes per season. In one case, he was in episodes airing a week apart. In one Anderson was bearded, in the other shaven, so they must have thought no one would notice. (Anderson was a popular actor in 50s and 60s television (not to be confused with comparably popular Richard Anderson); regular TV viewers would have quickly recognized him, regardless of makeup.) "The Rifleman" certainly revealed the range of his acting skills.
The writer apparently had never heard of the "real" Sherman brothers, so when they arrive, you're expecting them to sing "A Gun Full of Bullets".
This is one of those episodes that, like "The Guest" (see my review), is hard to pass rational judgment on. I'm giving it the benefit of the doubt, because it's the sort of story screenwriters are urged to write -- //the most-important story you can tell about your character//. But the whole thing has a "mechanical" quality -- events grind through to their predictable end with nary a surprise or dramatic twist. Anderson's fake beard is beautiful and convincing, though.