There is a connection, however oblique, between the Marx Brothers and Little Miracle Town. I first noticed this in the picture below, which shows Morris Gest (left) and some of the performers from Little Miracle Town posing with the Westinghouse robot Elektro the Moto Man (another of my obsessions). Elektro is seated on a motorized cart driven by Frank Buck (in the pith helmet), proprieter of the Jungleland attraction at the fair.
Note in the background in the upper right corner of the picture the heads of Chico, Groucho, and Harpo on a single winged, tuxedo-wearing body.
The puzzling nature of this picture remained unsolved until I saw the picture below in the online archives of Life Magazine.
The facade of Little Miracle Town was covered with this odd mural of flying celebrities holding hands. If you click to enlarge the photo, you'll probably recognize a few of the them, like Laurel and Hardy, Charlie Chaplin, George Bernard Shaw, Clark Gable, and many more.
If you look closely, you can see a portion of Harpo's hair (arrow) to the right of the barker in the detail below.
Further evidence can be seen in the film clip from the Prelinger Archives below. Between 10 and 18 seconds, you can see the three-headed Marx just above the heads of the crowd to the far right.
By the way, any resemblance between the depiction of the Marxes on this mural and the mythical multi-headed hellhound Cerebrus is purely coincidental, though those who had to work with the Marx Brothers might have thought otherwise.