Dunning Times Seven?
Ben Ohmart brought this book to my attention: Roger Paulson's Archives of the Airwaves. This is a ten-volume work that is seven times the size of John Dunning's classic On the Air. For the price of assembling the set it would be worth trying to get a copy of a volume through inter-library loan to peruse first. If it really is as well-done as Dunning's work the set deserves a place in every old-time radio fan's library. As a side note, browse the rest of BearManor's site. They have many nice works dedicated to old-time radio, including the only book written about the great Fibber McGee and Molly.