I had never heard of this, but I've read his Working, which was an impressive tome. I'll be checking it out.
Unusually enough, I found out about it while reading a book I had bought at City Lights Bookstore (Sabotage in the American Workplace: Anecdotes of Dissatisfaction, Mischief and Revenge), which cited it as a major inspiration.
The AWS back-end could be browsed or downloaded directly via AWS tools a ways back, and was about 600 GB last I'd checked. You'll have to sort out your own directory of content, however. Much of what's in there still isn't included in the official directory, again, at last check, though that includes numerous fragments and partial-tape interviews.
<https://studsterkel.wfmt.com/>
I strongly suspect that Working leveraged Studs's interviews, though all but certainly went beyond them as well.
It's also excellently curated. The transcripts are a plus that is often missing and the cross-linkage between transcript and audio is a wonderful gift to the listener.