[TUHS] Last officially distributed and currently available BSD version

All, I'm not 100% sure how best to ask this, but here goes... I own a copy of the CSRG Archives CD Set that Kirk McKusick maintained. I bought them ages and ages ago  (BTW, they are now all available on Archive.org). I dusted them off today because I had the brilliant idea that with my significant growth in understanding related to all things unix and ancient unix, that I might find them interesting and useful. They are interesting, jury's out on useful beyond being a broweasable historical archive of individual files. One of the CD's contains a 4.4 and 4.4BSD-Lite2 folder and is labeled releases (disk 3). I opened the 4.4 folder and it appears to be a set of folders and files I would expect to find on a release tape, but unlike a tape, which one could mount and boot from, I have no idea if this would be usable as install media (if you do, please let me know how). I googled about the two releases and although the same text appears all over the place about how Berkeley released one version, then removed some components, then re-released, and eventually wound up at 4.4BSD-Lite2, I could not figure out whether the word release meant sourcecode, installable media, or what. I gather a lot of this made sense back in the early 1990's but it's all a bit muddy to me in 2017. In trying to figure it all out, I came across a webpage talking about 2.11BSD (maintained into this decade) and another about 4.3BSD Quasijarus (also maintained in this decade?). Both descriptions contained the text, "It is the release of 4.4BSD-Lite, and requires the original UNIX license" (see http://damnsmallbsd.org/pub/BSD-UNIX). My sense of things after reading and browsing and such is that with regards to 4.4, 4.4BSD-Lite, and 4.4BSD-Lite2, they are either not released (4.4), encumbered and retracted (4.4BSD-Lite), or not installable (4.4BSD-Lite2)... Dang, so confusing... My interest is pretty much based on a strong desire to boot up a 4.4 system that as closely as possible maps to the one described in "The Design and Implementation of the 4.4 BSD Operating System" that I can experiment with as I'm going through the text. I think I understand the version history as it is described in various places, but I just can't figure how the last handful of versions relate to real media that is available to enthusiasts. Questions begging answers: What is the last bootable and installable media, officially distributed by Berkeley? Is that image currently publicly accessible? What is the closest version, that is currently available, that would match the os described in "The Design and Implementation of the 4.4 BSD Operating System"? Many thanks, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF