I understand and agree with your point about the general principal of providing hints. There were many such hints in the book that I didn't know about. Basically the whole of chapter 5, except for charcoal. A lot more than just chapter 5, too. I have been thinking about this for several years but I see now that my thoughts have been more about detailed construction plans for machines. I hadn't even thought about processes of extracting valuable natural substances from plants as in chapter 5. I was thinking more about building spinning wheels, looms, steam engines, early internal combustion engines, making steel, and much more. Also self study materials for math, science (especially physics and chemistry), medicine, and more.
A good example of what I mean about detailed plans, specs, and instructions is the book "A Charcoal Kiln Made of Cinder-Concrete Blocks" by Olson & Hicock, available from http://www.YourOldTimeBookStore.com
. I've been looking for a good book on making charcoal and I found one.
We are in agreement about needing additional books. Books that expand on every hint provided in your book. In many cases books that expand on some of those books will be needed. Books that provide detailed construction plans for every gadget used by every process like those processes in chapter 5 and later chapters. You provide some of this in the Further Reading and References section of your book.
It is possible for an individual such as myself to acquire many books (and even more PDF files such as the Appropriate Technology Library mentioned on page 299), but how best to secure/preserve the materials that I acquire? Simply leaving them for my descendants, even if safely packed, will likely fail to make them available some generations down the road. I like the idea of what has been done about seed vaults as seen on the Science or History channel. But I don't even begin to have funds for that. Accumulating available knowledge now can be done but making sure that knowledge is available when needed in the future is something else again.