I hate myself a little bit, but I posted an answer to the 'BSD license origin' in this twitter thread
that people might find interesting.

Please note the caveats at the end of the thread: This is a bare outline hitting the high points taking only data from release files with no behind the scenes confirmation about why things changed, nor in-depth exploration of variations that I know are present, nor do I got into examples from various USENET postings from the time that stole the license for people's own different uses.

Nonetheless, I hope it's useful...