I recently updated my English key on the Internet Archive for the 1928 Gregg shorthand book The Raleigh Rainbows.
That 1928 shorthand book was created as a learning tool for the 1916 Gregg shorthand manual. It soon became obsolete after the Anniversary manual came out in 1929.
The Raleigh Rainbows shorthand book was only available for three years. It was not renewed with the Copyright office and fell into the public domain in 1957. I was able to find a copy of the shorthand book and scan it, and I put it on the Internet Archive in 2011.
I created the English key in 2012 and put it on the Internet Archive. There was never a published key from the Gregg Publishing Company. It was very challenging to create the key because the shorthand book is full of mistakes and proportion errors.
A few months ago, I was able to get a scan of the unpublished draft of the key from the Gregg Shorthand collection in the New York Public Library. That Gregg draft key has a lot of mistakes and is probably not suitable to use as a key for this book. I was able to update my 2012 key with the help of the unpublished Gregg key.
Here is a link to my updated English key on the Internet Archive:
https://archive.org/details/TheRaleighRainbows-EnglishKeyForGreggShorthandBookV8
Here is the link to the Raleigh rainbows shorthand book on the Internet archive:
https://archive.org/details/TheRaleighRainbow-WrittenInGreggShorthand