​FYI:  "Early" fsck was developed before SCCS and PWB 1.0.   Version control was what Ted has on his disk at the time.   At some point, I would have expected that he put it under control @ Summit and wnj is likely to have done the same at UCB.​  What is in the BSD repository is about 3-4 years into development.

As I said, Ted taught us all to use DOS-11 backup to make an image of his RK05 to small of reel 9-track tape [800 bpi IIRC].  As I said, at one point I had a couple of those tapes.  I looked for the box of them from CMU but I free I may have disposed of them when I lost access to an 800 bpi drive [I now have one, although it has an issue loading tapes I need to fix].

Clem