To forestall those who haven't looked: the good news is that
the papers from Volume 2 of the manual were included in /usr/doc
on the V7 tape; the bad news is that the C Reference Manual was
omitted. Here is /usr/doc/cman in its entirety:
Sorry, but for copyright reasons, the source
for the C Reference Manual is not distributed.
Presumably the problem was that the Reference Manual was published
as part of the a real book in 1978.
I forget just what Tony was after in the first place, but maybe
some of the stuff on Dennis Ritchie's home page will help:
In particular the Sixth Edtion version of the C Reference Manual