
Interestingly, I’ve recently come across versions of this same sort of tickler file recommended in mid-20th century textbooks for filing and indexing in business contexts:

Cadwallader, Laura Hanes, and Sarah Ada Rice. 1932. Principles of Indexing and Filing. Baltimore; Chicago: H.M. Rowe Company. page 134: https://archive.org/details/principlesofinde0000laur/page/134/mode/2up

Kahn, Gilbert, Theo Yerian, and Jeffrey R. Stewart, Jr. 1962. Progressive Filing and Records Management. 1st ed. New York: Gregg Publishing Division, McGraw-Hill Book Co., Inc. page 190: https://archive.org/details/progressivefilin0000gilb/page/190/mode/2up
The careful observer will notice that both of the photos in texts by different authors nearly 30 years apart are the same! I would suspect that they’re from a manufacturer’s catalog (Remington Rand) earlier in the century. It’s even more interesting that one can still quickly create such a set up with commercially available analog office supplies now.