It always takes a little extra effort to comment but I thought that I would also add that I've enjoyed seeing a new source tapped for a somewhat different perspective on Duluth history. I actually clicked on this story again because I saw the additional comments and was interested in some more context on that strange broadcasting booth. I like the idea of downtown being so busy that someone thought it needed something like an air traffic control tower. 

I'll add in that extra context myself by quoting from a 1997 UWS master's thesis on the history of WEBC:

To increase the visibility of WEBC's deejays, a glass-walled on-air studio was built on the roof of the WEBC Building, 4 stories above Superior Street. It was called the WEBC Traffic Tower. The listening public could see, and wave to, the deejay. The deejay, for his part, shivered in the cold and sweltered in the summer sun in the greenhouse-like box on the roof (Latto, 1997). Also on the rooftop was a mast with the WEBC Weather Beacon, a light that could be color-coded to the forecast. The announcer would point out that the Weather Beacon was flashing red or a steady yellow -- whichever indicated what the forecast predicted. If they knew the code, passers-by could get a forecast at a glance, and at the same time, a reminder that WEBC was providing the service (R. Johnson, 1997).