Thanks - I've already sent Lou a note, which he has not yet responded.  I should have remembered he was user #1.

So, my guess is that Lou had 4th edition at this point.

Although from your comments, I'm a little surprised Berkeley went back that far, give than BSD (1.0) was all sixth edition and post Ken's sabbatical.   The Industrial Liaisons Office (ILO) in EECS which ran all of that had existed for a number of years (since the late 1960s).  They were already distributing things like SPICE and SPLICE.  So the idea of giving away there SW work was really well ingrained in the Berkeley way of doing things in EECS.   

BSD (1.0) in fact used the original SPICE distribution process in the ILO (as I suspect Ingress would have also a few years later).   While folks think of the later CSRG stuff, that was later - once UCB got the support contract from DARPA.  Originally it was just the fruits of the labors of the folks in EECS being package and distributed to the folk what worked with them as managed by the ILO (which was originally folks like AT&T, IBM, HP, Tektronix, DEC, Intel, Fairchild, etc...)

So it means that UCB was hacking privately without taking to Katz@ NYU, or the Columbia and Harvard folks for a while.   I need to ask Lou what he remembers.   UCB was not connected to the Arpanet at this point (Stanford was), so it's possible Ken's sabbatical openned up some channels that had not existed.   [UCB does not get connected until ing70 gets the vdh-interface up the hill to LBL's IMP as part of the Ingress project and that was very late in the 70s  - not long before I arrived]. 

On Fri, Sep 1, 2017 at 3:05 PM, Jeremy C. Reed <reed@reedmedia.net> wrote:
> "A Quarter Century of UNIX" says:

And in Salus later book, The Daemon, the Gnu, and the Penguin (which I
published for him), he quotes Allman as using 4th edition at Berkeley.
Allman also told me (for my BSD history book in progress), that when he
got involved INGRES was running on 5th Edition and he helped with the
transition to 6th Edition.

Also McKusick's 1985 article "A BERKELEY ODYSSEY: Ten years of BSD
history" says the version 4 tape was delivered in Jan. 1974 (and used on
PDP 11/45) and INGRES was running the newly-available Version 5 of Unix
in the spring of 1974 (on PDP 11/40).

(Following from my book...)

The University of California --- via the
San Francisco Medical School Campus --- was recently
licensed by Western Electric to use Unix. (Fortunately, the
licenses from Western Electric were per-organization rather than
per-computer.)
So Fabry was able to get started with Unix much more quickly than anyone
would have imagined.\cite{fabry2}
%
% NOTE: here is the license for it: archives/1970s/UC_License_4thEd.pdf
% effective Dec. 1, 1973, licensee was the Regents of the Univ.
% NOTE: it says for the location of School of Medicine
% signed on Jan. 7 and 16, 1974
% 2.01
The license allowed use solely for academic and educational purposes.
% 4.05
In addition, the University was prohibited from sharing the software
--- including its methods or concepts --- to anyone other than the
University employees or students.
% NOTE: no version of Unix is mentioned in the license