I recently came into possession of a number of documents from the library of Joybubbles (aka Joe Engressia) via Phil Lapsley. There's some interesting documents that I'll hopefully be able to digitize eventually. Here's the first: Telephone Theory and Practice, Automatic Switching and Auxiliary Equipment by Kempster B. Miller, 1933. It was photocopied by someone at AT&T and sent to a reader, since Joybubbles was blind. Because of this a lot of the photos are of poor quality, but the text is readable. It's a nearly 500-page book so someone went to a serious amount of effort to get it to him.
The PDF is large, about 42 megs. It can be found here:
These were documents that Steven and I rescued when we were cleaning out Joybubbles' apartment after he passed away in 2007. Thanks, Sam, for digitizing this particular volume and for the many other things you do to preserve telephone history. Joybubbles would have appreciated it. As he was fond of saying, "knowledge shared is knowledge expanded."