Not that you need more to read or research, but I had to link to The Filling Station for something, and I saw this that may be of help.
Chevrolet Service News. The article says it is info sent to Chevy dealers for 1927 model years and on.
There is a link where you can order them but perhaps the GM Heritage Center can help you with that. We have called them in the past (like 8-10 years ago) and they were very nice. Worth a try.
Peg
