> Then I try CUPS via http://localhost:631. On the page displayed by CUPS 1.4.8 (or following any of the links) I can find nothing about re-starting a stopped printer, print queue, etc.
It's in the "maintenance" drop-down list after you select "Printers" and then the name of your printer. Besides "cupsenable", this is also equivalent to:
or by changing the ErrorPolicy line in /etc/cups/printers.conf.
This is for a more recent version of CUPS (1.5.2), and I'm not sure how well it translates to version 1.4.8. The maintenance drop-down, at least, has been around for quite some time.