I can not speak for Australia. I lived the Fifth, Sixth and Seventh Edition changes in the mid-late 1970s.

    At CMU, in the USA we had an early /34 running Fifth Edition in the EE Department summer of 75/76 ish - right after the /34 came out.  There were lots of 40's around campus and at the time were popular because CMU hacked them (i.e. the E or Extended version of the 40), but I remember Gordon Bell got the EE Dept a "deal" on the new single board 11 - i.e. the /34 & it was significantly cheaper.

    We got V6 shortly there after when a couple folks made a road trip to NJ to see Ken and the EE system did not run V5 very long [frankly, I do not remember much about it].   I do remember that we had boot strapped /34 from some 11/40E's in CS - I remember the lack of switch register issue, but I also seem to remember it was easy fix in m40.s.  I've forgotten all the differences, but I recall that they were small.  I do have memories of going back and forth between the CS and EE bldgs a couple of times until we got it right.

   The bigger issue that bit us was we had to careful about the fact that the CS folks had implemented CSAVE/CRET in the WCS of the 11/40Es and hacked on the C compiler to generate that - so binaries from CS could not move to EE unless that hack was turned off  [BTW: That job in EE was my first experience with C].

      The late Ted Kowalski showed up at CMU a few weeks later for his OYOC year and updated the EE machine to be V6++ system [and also he had copies of the proofs from Dennis's upcoming book on C ].  Being CMU, we had a lot of BLISS hackers at the time - so Ted singing C praises was quite a stir -- I was not yet really indoctrinated with the merits of C and remember arguing with him since at the time the C compilers were not nearly as polished as the CMU BLISS compilers - although it ran natively which BLISS/11 could not do].

    At the time, a big thing Ted did was introduce us to stdio.   Until then most of the our C code was pretty hackneyed - I seem to remember something called the portable C library for V6 (I do not remember it as part of V5 but have been).   However, Ted's V6+ compilers used stdio and it quickly because the EE standard.   They must have migrated to CS, but I've forgotten because by them most of my hacking was on the EE system.

     Ted was working on this really cool program to fix the file system [fsck] - although a number of us worked with him and it was working with that code - that I started to see what a great language it was and ended up writing way more C than anything else.

     I would clone the EE /34 system for a new job at CMU's Mellon Institute but by then DEC had created the /34A [I've forgotten the differences].  Mellon was the first time I ran into a UNIX vs. XX war.  One of the grad students wanted to run RSX-11 - since DEC "supported it."   As a lowly undergrad I was really pleased I won when the EE prof behind  Mellon Institute agreed we "seemed to have something" working really well in the Dept [plus it must have helped that the Biomed team, also decided to clone the EE system for their research and not use RSX].

      As for the 11/60, upon graduation, I spent my first weekend in Oregon in late 1979, helping Steve Glaser update the Teklabs /60 to be more CMU like - but that was likely based on V6.  I do not remember when we cut V7 in at Tek, it had been released and I don't remember the details for CMU - we had to be running V7 by the time I left.  At Tek, by the end of 1979, we had done such a good job with the /60 that we managed to get an 11/70 (without any budget for it which was quite a trick).  So, I spent my first Oregon Christmas bringing V7 up on that system - with the infinite storage capacity of 3 RP06s [oh boy].  My faint memory is that Tek had a V7 license, but Steve had not yet managed to get V7 running on the /60, only V6.

     Also, early in Winter/Spring of '79 before I had left  Dan Klein and I had gone on strike to force CMU to buy a commercial license for Mellon institute -- which was not using UNIX for teaching for paid research.   CMU would be the first University to get a commercial license, I believe Case-Western followed suite the next fall when Fred Park returned from Tek-Labs after heard me talk about what CMU did that summer.

Clem