I've written for L-V and can probably provide a copy of the original AA-320 training manual to any AKer who may get the set.
The last NTSC Zenith was engineered by L-V for training in 2000. A friend who was the chief engineer lent me a 'chassis' from the last, small run. I wanted to compare 1954 CT-100 color hardware to 2000 solid-state hardware and this shot for my site was the result:
http://home.att.net/~pldexnis/potpou...ooldandnew.jpg
BION: Lab-Volt once wanted a basic course in vacuum tubes and so I wrote a short lab manual for them back in 1981. Curiously, that manual/course sold -- never well -- but on and off until the final edition in early 1999!