> (The results also show that I need to examine the apparent timing mismatch between the First and Second Editions.)

Something something, naming things, cache invalidation, timestamp mismatches and off-by-1 errors :)

It could just be as simple as being a later "final" copy of V1, made when it was "done".

Ongoing posts about the tape discovery and work: https://discuss.systems/@ricci/115748594116050292

Previously:

Unix v4 Tape Found

https://news.ycombinator.com/item?id=45840321