I'm using and programming with Unix since 1986. If you are interested by Unix History => https://minnie.tuhs.org/TUHS/

4.3BSD is a very important development in the history of UNIX, and this old unix still usable in 2023.

To install 4.3BSD on simh emulator (http://simh.trailing-edge.com/)
you could get all the information on Bob Eager web site here:

http://www.tavi.co.uk/unixhistory/quasijarus.html

This file 4.3BSD-dec-vax.tar.xz contain an allready installed OS that you can start with sim-h emulator.

If you are lucky owner of real vax hardware, the full /usr/local with GNU tools ported is here: local.tar.gz

You need at least the new /usr/local/bin/date GNU command, because the original release date doesn't allow you to change date after 1999,31,12.

bash-2.05b, gcc, and make, is need if you want to be able to compile something not from previous century.

OLD GNU sources (quickly and dirty patched AND compiled)
Archive include binaries (install with make -i install):
bash-1.14.7.tar.gz
bash-2.05b.tar.gz
bash-5.2.15.tar.gz
zsh-2.2.tar.gz
zsh-2.5.0.tar.gz
make-3.75.tar.gz
make-3.82.tar.gz
make-4.4.tar.gz
binutils-2.8.1.tar.gz
tar-1.11.8.tar.gz
bzip2-1.0.8.tar.gz
gzip-1.2.4.tar.gz
gcc-2.7.2.3.tar.gz
gcc-2.95.3.tar.gz
vim-5.1.tar.gz
bison-1.25.tar.gz
bison-2.2.tar.gz
flex-2.5.4.tar.gz
findutils-4.1.20.tar.gz
gawk-2.15.tar.gz
m4-1.4.19.tar.gz
grep-2.4.1.tar.gz
perl-4.036.tar.gz
sed-2.05.tar.gz
sed-3.02.tar.gz
zlib-1.2.13.tar.gz
ncftp-2.4.3.tar.gz
wget-1.5.3.tar.gz
gettext-0.14.6.tar.gz
termutils-2.0.tar.gz
termcap-1.3.1.tar.gz
autoconf-2.52.tar.gz
perl5.005_04.tar.gz

OLD sources not realy fully ported but part are usable (try make -i install) (ugly patched to compile):
TOFIX-coreutils-5.0.tar.gz
TOFIX-glibc-1.09.1.tar.gz