Allen, thanks for the tip. I recently did a Thornhil big-band program and came across a passage from Zwerin's book, quoted in a W. Balliett piece, I believe, that I incorporated into the show.
Of course it isn't just a question of time; it's a question of performing all the hard labor of research and improving my ability to write about jazz. But Thornhill's birthplace is just up the road from here, and nobody (that I'm aware of) has written a book about him before. His centennary is coming up in 2009, which is why the thought's been budding in my brain.