Apparently the book is free as in beer, not free as in freedom; derivative works can't be distributed and some people argued that for a decent ebook experience you needed to make adjustments to the book. As no one wants to be challenged by Google in court, there were no volunteers last time I've checked.
Then publish the script on github: https://github.com/captn3m0/hoshruba
https://creativecommons.org/licenses/by-nc-nd/4.0/
You are free to:
Share — copy and redistribute the material in any medium or format
/No need to be a lawyer. That's covered in law case study 301 and 302.
In the CC license linked, the following text reads like making an ebook would be alright. The helper text on "remix, transform or build upon" says "Merely changing the format never creates a derivative."
If you want, you can click on the "time" of their comment (ex "3 minutes ago") which will bring you to a page that you can always reply to (at least in my experience).
When the world goes down, Calibre comes with me.