I bet the GZ generated a few UFO sightings, though the modern concept would not actually start for another 18 years.

My grandmother, who worked as a secretary on Fifth Avenue in the late 1920s and early 1930s, saw the GZ paraded up that famous street right outside her office window. She knew what it was and it still made quite the impression on her and everyone else that day. She also saw from the same window Charles Lindbergh getting his ticker tape parade after his famous cross Atlantic flight two years earlier.

She also remembers the total solar eclipse that was visible from NYC in 1931 and how the office cleaning lady ran around shouting that the world was coming to an end.

But to get back to Mars Zepplins, would one be feasible for exploring the Red Planet? It has also been discussed here before regarding Titan as well, though I have also read that a helicopter would be better for its environment.