Apple did not "give away" that documentation, you had to buy it. It was published by Addison-Wesley.
I was piled into a pickup truck with five other folks, as we went up to the bay area for an early (perhaps first) incarnation of MacWorld, where we saw all sorts of wonders. But one of them, hot off the presses, one the Inside Macintosh Vol 1-3 book.
It was $80 ($250 in today's dollars), I think, and I snatched one up. Mind, it was not easy to just plonk down $80, but that the zany stuff we did back then. Boy, were computers expensive!
Hard bound, paper sleeve, beautiful text and diagrams. Very nice.
Outside of that, I really like the Macintosh Revealed books they have here.
It would be nice to see a stack of MacTech archive issues as well.