Interesting question. What was the "Shadow Password Suite" back then can be found in different places these days. For example the package Debian should be "shadow" but Red Hat has the binary in the "passwd" and the initial /etc/{shadow,passwd} in the "setup" package. I guess you'll have to zgrep some source packages for a (common) references if any. If you OTOH would want to talk to people with
experience in alternative shadow schemes try OpenWall, see
www.openwall.com/tcb/.