I do not know of Luhmann’s paper. My understanding of Luhmann’s zettelkasten comes via Ahrens book.
I saw your comments re trying an analog zettelkasten. I don’t know why you would do that. It seems like deciding to use a paper payroll system for a large company because you read about how that was done before computers.
You might want to investigate the new category of software that has recently been developed - Roam and Obsidian being two leading examples, although there are others. There is tremendous interest in their user communities regarding how to develop zettelkastens.
Roam has run 4 “book clubs” using a public Roam instance devoted to analyzing Ahrens book - with Ahrens as a guest speaker. Hundreds of Roam users have participated in each of these “book clubs.”
I’ve been using Roam since October. The Roam equivalent of a draft in Drafts is a “page”. Pages contain “blocks.” Roam uses an outline metaphor, and every bullet is a block. Pages and blocks can be “referenced” - which is something like a link, but more powerful. Since October my graph has grown to 1,491 pages, with 21,844 blocks and 11,348 “references.”
I still use Drafts - a dozen or more times every day - but Roam has taken over the management of my life. I can’t imagine doing it manually.