On 26.02.2022 22:45, Brian Walden wrote:
[...]  Sometimes you could find an early version of the
Bourne shell in /bin/nsh (new shell) in v6.
The 7th edition release of the Bourne shell contains a
  char version[] = "\nVERSION sys137    DATE 1978 Nov 6 14:29:22\n" in msg.c
which was unfortunately not used, remained unchanged in descendants, and got removed with SVR2.

I often wondered about the versions bevore "sys137".  I thought they were just lost.
So Brian's remark got my attention. I haven't found anything in the 6th ed variants I found in TUHS UNIX Archive.

Does anybody know how to find a Bourne shell before 7th ed?

Thanks and Cheers
Sven