worldcat lists the institutions with this book https://search.worldcat.org/title/1048005393, you'll probably have to show up in person. You may be able to do an inter-library loan if your local library doesn't have the book, you could get it from a sister library. However, the only public library that lists having the book is the Austin Public library in Austin, Texas.
Something like that is probably technically possible, but you'd need to do a bunch of work.
Plex Plugins can't provide media sources anymore, so you need to do the trick plex_debrid is doing where you add stub sources to the plex server library and serve the files from a virtual filesystem.
You might be able to re-use the plex_debrid code but use youtube-dl instead of rclone
This uses ffmpeg under the hood and muxes the file into a .m4a file without transcoding. Basically keeping whatever compression youtube used for the audio (which is some sort of mpeg4 compatible audio, probably depends a little bit)
This still recompressed, but it's the best you can do using youtube as the source.
uploader (almost certainly, but theoretically you could skip this step if you encoded your video well) compresses audio
uploader uploads to youtube
youtube re-compresses the audio again (almost certainly transcoding into a different codec)
worldcat lists the institutions with this book https://search.worldcat.org/title/1048005393, you'll probably have to show up in person. You may be able to do an inter-library loan if your local library doesn't have the book, you could get it from a sister library. However, the only public library that lists having the book is the Austin Public library in Austin, Texas.