Worzel - I had a similar 'experience' with a windows 98 re-install -drive there, light flashing, draw not opening or closing and not in Device manager.
(Subject to trying WDTBD's alive/dead test), and if you are feeling brave enough to poke around inside the beast, gently pull off the multi-pin connector (not the white power one) on the back of the CDR and then boot up. Close down, reconnect the plug and reboot. It just MAY find it this time? Might be worth a try.
You can setup an 'autoexec.bat' on a floppy drive to run the CD rom in DOS to check it too.