Bob Lang posted a video of a film shot in the Martin Guitar factory in 1939. It’s a wonderful look at production fine-woodworking in the heyday of the Martin factory. It reminded me of a book I read a few years ago: Clapton’s Guitar: Watching Wayne Henderson Build the Perfect Instrument by Allen St. John, which goes into considerable history of Martin guitars and why the old ones are considered so much better than the new(er) ones. It’s a great read, one that I enjoyed immensely and have recommended often.
Please ask for it or order it from your local bookseller. ISBN 978-0743266369. Yes, they have it at that online bookseller but give your community bookstore a chance first. They need you.