Some time in 2017 a contributor named Erica Fischer made digital scans from
historical comb-bound Usenix printed manuals for both 4.2BSD and 4.3BSD, and
uploaded them to archive.org.  Here is the 4.3BSD version:

https://archive.org/details/uum-ref-4.3bsd
https://archive.org/details/uum-supplement-4.3bsd
https://archive.org/details/upm-ref-4.3bsd
https://archive.org/details/upm-sup1-4.3bsd
https://archive.org/details/upm-sup2-4.3bsd
https://archive.org/details/smm-4.3bsd
https://archive.org/details/uum-index-4.3bsd

The 7 *.pdf files collected in this directory have been downloaded from the
links above.