The Saga…
1. I booted in to the volume with the Supplemental on it to ascertain if my password would work as as I presumed.
2. I then concluded (perhaps foolishly) that something must be interfering/conflicting when I entered my PW in Terminal.
3. So I rebooted in Safe Boot and then tried to execute the commands as suggested. And voilà . The file is again hidden. Good news me thinks, indeed a very clever chap that Harvey guy…
4. But speaketh not too fast. When I attempted to boot out of Safe Mode, I discovered the volume was no longer bootable. The "mach_kernel" was not made invisible, it was deleted!
5. My vocabulary was then exercised to its full…
6. I have now replaced the "bad" volume with a known (pre-Supplemental) volume and all is again, right with the world. At least for now.
7. Perhaps I had a corrupted download--I really haven't a clue, only guessing. For sure I'm confused. Not since 1984 have I had such grief with an updater.
By the time I recover from this mish-mash, Mavericks will be released; and I am certain to give it go. In any event, the new OS will again be on an external backup.