Something reminded me of the “Applied Secretarial Practise” book I got 10 or 20 years ago. It is not at all useful for shorthand, though there are some “motivating” paragraphs in shorthand near the end from which I did pick up the useful phrase “as far as” s-f-s which was not in my phrase book.
However it is a glimpse into the secretarial world of the 1920s/30s — a more well defined and steady environment than exists today, and a fascinating survey with pictures of the ‘modern’ machinery that was sometimes used, as well as the paper forms, and filing and accounting methods that was required.
My book had 1934 on it, authored by Sorelle and Gregg (though I expect Gregg only ‘approved’ Sorelle’s work). I’ve not encountered any mention of it since then.