The movie Howard and Millie see at the theater is "Two in Love" starring Ed Olson and Viola Kern. Both the movie and the actors are fictitious.
This episode marks the third time that Allan Melvin plays a tough guy/troublemaker who eventually backs down. The other two are Lawman Barney and Barney's Uniform.
The building where Howard confronts Clyde is the new paint and wallpaper store where the old Mayberry theater used to be.
Andy and Goober motion to Clyde that Millie is down the block at the movie theater. However, that front had been recently renovated into an office building for some other production, so all of the scenes at the theater were shot in closeup on the Desilu soundstage.