Modular scripts project: looking for information about writing instruction

Last December I asked TD members for help identifying examples of modular type and lettering. I'm happy to say that the outline of the first stage of the project is drafted, and with a little luck and some money from my school I'll be visiting the Letterform Archive in January to gather information and better images to complete it. I hope to share this work publicly in the not-too-distant future.

Now I'm starting the second stage, which is looking for conceptual and practical antecedents of modularity in the history of writing.

One important strand of this genealogy is in writing instruction. Teachers of writing often break down characters/letterforms into segments or components to show students how to shape them properly.

I'm looking for help identifying significant examples of manuals or other codifications of writing instruction that use this approach, from any and all eras. Think:
  • diagrams of radicals for Chinese calligraphy
  • Dürer's instructions for writing blackletter in his 1525 painter's manual
  • 20C brushlettering/signpainting manuals
—etc., etc. Please don't hesitate to offer what might seem to you like obvious suggestions—I'm grateful for the help and don't at all mind sorting through recommendations that duplicate what I've already been able to find myself.