Did he reply back with the book?
But I managed to track it down elsewhere. I've thrown it onto my static site, so that it's easy to get to. My understanding is that it's in the public domain, so this is fine. If I get told otherwise I'll take it down.
https://riazarbi.github.io/files/Work%20simplification%20as%...
The netlify app is a fork, like a code fork, of the original document. Which is to say, they have taken the original work, transcribed it to a digital format, and will now evolve it.
I don't know if that just went way over my head or if it was not clearly communicated, but there you have it.