Yeah I have emailed Kevin Crenshaw but he stated the project is "abandonware" at this point. He said to search for it online. So far no luck with version 3.0. It would have been fun to try playing with some old code in a VM :)
I don't live anywhere close the the Library of Congress, so not easy for me to get a copy there :(
Anyone can get a reader card at the Library of Congress if they have a photo id and are at least 16 years old. I'm not sure how you access computer files there, though. The reader card has to be obtained in person. With the Library of Congress closed to visitors because of COVID-19, I imagine it's not possible right now.
I am not familiar with how libraries work in the US. Can anyone get a library card with Library of Congress? They have the floppy images:
https://www.worldcat.org/title/spontaneous-assembly-for-cc-a...
EDIT: http://300m.us/docs/computing/ Has a link for purchase which 404 but to an existing site. Maybe Kevin is the friendly type?