On Tue, Dec 05, 2017 at 05:33:02PM -0700, Warner Losh wrote:
>   From the tuhs web site:
>   "This is a set of addenda to Seventh Edition Unix, possibly put out by
>   the Labs."
>   and
>   "The identity of the person who donated them is unknown."
>   Two questions: Was this put out by the Labs?
>   Second: There was recently a discussion about a tape found at some
>   public location during an early Unix user group meeting. Is this that
>   tape?
>   Warner

No. I had to search my own archives. From this list in 2002:

The mythical `50 bugs' tape, described in Peter Salus' book `A Quarter
Century of UNIX' has been found lurking in the Unix Archive. You can
find it in Applications/Spencer_Tapes/unsw3.tar.gz as the file
usr/sys/v6unix/unix_changes.

And here is the relevant paragraphs from QCU:

   Lou Katz’s version is a bit different:

      A large number of bug fixes was collected, and rather than
      issue them one at a time, a collection tape (”The 50 fixes”)
      was put together by Ken. Some of the fixes were quite important,
      though I don't remember any in particular. I suspect
      that a significant fraction of the fixes were actually done by
      non-Bell people. Ken tried to send it out, but the lawyers kept
      stalling and stalling and stalling.

      Finally, in complete disgust, someone "found a tape on
      Mountain Avenue” which had the fixes. [The address of Bell
      Labs is 600 Mountain Avenue, Murray Hill, NJ.]
      
      When the lawyers found out about it, they called every
      licensee and threatened them with dire consequences if they
      didn’t destroy the tape, after trying to find out how they got
      the tape. I would guess that no one would actually tell them
      how they came by the tape (I didn’t).

Cheers, Warren