There was a 1962 manual called "Electron Tube Design" put together by RCA, which was not meant for public release, but was intended for internal use in training new engineers in their tube manufacturing operations. There are several chapters on CRT theory and manufacturing techniques, both for television and oscilloscope types. Hardbound original copies are pretty rare and expensive (estate sales from former RCA employees are about the only source), but it is now available online in various formats here:
http://archive.org/details/ElectronTubeDesign
This is a KILLER reference for the serious tube geek! Covers every kind of tube that RCA made, from ordinary receiving types through camera tubes, industrial and broadcast power tubes, microwave tubes, and of course CRTs.
Another great reference specific to CRTs is "The Cathode-Ray Tube: Technology, History and Applications", by Peter Keller. A bit pricey via Amazon, but AFAIK still available directly from the author a bit cheaper.
http://www.amazon.com/The-Cathode-Ra.../dp/0963155903
See 7th listing down the page here:
http://www.tubecollectors.org/for_sale.htm