I am running PCtools disc recovery utility, which at the very least seems to be indicating that most of the missing files still exist, but somehow were erased.
Worst case, I lost some incomplete work and have to reconstruct some financial stuff.
The mystery is, how this happened.
Later PCtools File Recover has not actually been much help - it has confirmed that the files are still in some sense there, but it doesn't seem to be able to recover them in any form that WordPerfect can read. Word won't open them either. It told me that they might not work if I recovered them to the same disc, so I got them to write to a CD. That didn't help either.