Update #2.
I booted booted to RAM (no lupusave), and before installing anything at all, tried printing both to CUPS-PDF and pdf_writer. Neither produced an output -- neither asked for a filename...
checking the job status shows pdf_writer as "completed", and CUPS-PDF as "failed".
Again, the dates on each job is shown about 48 hours in the future...
Update #3: OK, now this is REALLY, REALLY, REALLY SILLY...
What apparently broke the printer was changing the Hostname from "puppypc" to something else.
Now why would this name make any difference to the local PDF "printer"?
I guess that what remains to be seen is whether naming every computer on my network "puppypc" will cause issues...
Update#4: Booting up my previously fully configured and working lupusave (but with broken printer), I edited /etc/hostname and changed the name back to puppypc. Rebooted and reloaded this lupusave, and now the printer works...
Is the printer hard wired to look for that hostname, and thus a name change breaks the path?... What gives?