In my travels, I've come across several old Illinois Bell buildings converted to other uses. With computerization, conversion to wireless, they no longer needed all the old clerical offices and garages. Just like Chicago public schools, the buildings I know seem to have distinguishable architectural style.
On Montrose and Linder they coverted the building to Vaughan School.
One Northwest highway and Bryn Mawr they converted the building to Sweet Connections bakery.
I seem to remember a building on Western Ave. north of Lane Tech and Addison.
Another building I remember seeing is on Northwest highway, don't recall if it is still in use.
I would be curious to know what they did in these buildings or other closed buildings now being used for other purposes.