When Opie and Andy are talking in front of the theater there is a poster for a movie titled "Bells for Heroes." The film is fictitious and the poster is actually a modified poster for the film Hell Is for Heroes (1962).
The sword that Clara displays as having been used during the 1762 'battle' was specifically a U.S. Cavalry saber, in the design of sabers produced between 1858 and 1865 - a full century after the battle. This is in keeping with the tall tales being told of the skirmish, none of which seem to match with one another. More specifically, there is every reason to believe the sword might actually have been genuine, given the natural patina on the brass, iron, and leather components. Surplus Civil War swords, even though the war had ended nearly a century before production of the show, were still commonly sold as surplus in the 1950s and 60s. Such genuine articles were often purchased for use as film/television props and set pieces, as there wasn't much difference in price between the real items and their reproductions.
Andy says that his ancestor, Carleton Taylor, was one of the first settlers in Mayberry and that Mayberry was almost called "Taylortown." There actually is a Taylortown in North Carolina. It is located next to Pinehurst, North Carolina.
When Andy is speaking to Opie in front of the Mayberry Theater, we can see that the cost of tickets at the Theater is 35 cents for Orchestra and 25 cents for Balcony.
As Andy and Opie move away from Tom Strongbow's gate the tire tracks from Mr. Foster's Cadillac can still be seen in the dirt behind them, left over from "The Foster Lady" just two episodes before.