Here are some Google books links for full volumes of the Gregg Writer and the British Gregg Shorthand Magazine. I found these recently. A few years ago I posted several links for earlier issues of the Gregg Writer. These were not there at the time.
I realize that most of these are available on the Internet Archive as separate magazine issues.
The difference is that these Google Books were scanned from bound volumes of the magazines from universities and have much higher resolution than those found on the Internet Archive.
The Gregg Writer issues on the Internet Archive were scanned at very low resolution from an ancient set of microfilms created from bound volumes located at the library of Congress.
Here’s what I found:
VOL 2 1900-1901 Incomplete:
https://books.google.com/books?id=guNDXraeNgQC
Vol 14 1912-13:
https://www.google.com/books/edition/The_Gregg_Writer/AaQKAAAAYAAJ?hl=en
Vol 15 1912-13:
https://www.google.com/books/edition/The_Gregg_Writer/RZcKAAAAYAAJ?hl=en
Vol 19 1916-1917:
https://www.google.com/books/edition/The_Gregg_Writer/BewCAAAAYAAJ?hl=en
Vol 21 1919-20:
https://www.google.com/books/edition/The_Gregg_Writer/u9sCAAAAYAAJ?hl=en
VOL 27 1924-1925:
https://books.google.com/books?id=0YehvWrJ0_AC
VOL 28 1925-1926:
https://books.google.com/books?id=A2BX37tyKwIC
VOL 29 1926-1927:
https://books.google.com/books?id=rTwzjTOv1mwC
VOL 30 1927-1928:
https://books.google.com/books?id=lWmxpN26G6cC
VOL 31 1928-29:
https://books.google.com/books?id=gqYL1noIG6QC
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Gregg Shorthand magazine (British):
Vol 15 1927-28:
https://www.google.com/books/edition/The_Gregg_Shorthand_Magazine/UB8jAQAAMAAJ?hl=en
Vol 16 1928-29:
https://www.google.com/books/edition/The_Gregg_Shorthand_Magazine/qx8jAQAAMAAJ?hl=en