Three of the cast members in this episode also appeared in the radio version of "Gunsmoke" as regulars: Howard McNear (as Doc), Jeanette Nolan, and Frank Cady.
As Matt notes, the rifle carried by Aunt Thede is something of a rarity, a Colt Revolving Rifle Model 1855. This was similar in principle to Colt's more famous revolving pistols, but was built as a long arm. Although it was used in the early days of the Civil War, it quickly fell from favor due to its reputation for accidentally firing more than one chamber at a time, putting at risk the shooter's hand that was grasping the forestock or barrel. The introduction of the self-contained metallic cartridge could have solved that problem, but the Colt company in the 1860's did not believe that innovation, which made possible the superior lever action rifles such as the Henry and the Spencer that quickly eclipsed the Model 1855. Having been made in relatively small numbers, Model 1855 rifles are now prized by collectors.
Dyan Cannon would marry Cary Grant 7 months after this episode aired.
Aunt Thed tells Festus she ain't looking to marry him as there are too many years between them. In fact, Jeanette Nolan is only five years older than Ken Curtis.