Baffling question, indeed.
I am supporting 4popoid at this point for a couple of reasons but I am still not sure.
The vehicle in the background looks to be something American, even including the license/registration plate.
The dress of the spectators in the photo seem to be "working class" folk and could possibly be Americans also.
My main concern is the shades over the three windows which is not really typical of American coachwork but usually more European.
If the bodywork is truly American, I would hazard a guess that it has to be either a car bodied in the New York area or the Los Angeles area as Hispanos were truly rare in this country and most often to be found on one coast or the other.
Go for it 4popoid, I am stuck.
Bill