There were backups on Carbonite, but that contract terminated and the data is no longer available. A major sin, of course, but trying to revive the unit so that it can be correctly backed up. A drive failure would have been easily recoverable, but the cabinet power failing is not and was not anticipated.
Most likely, it is RAID 0 or 5 (striping).
Buffalo has been limited in their support as the unit is 10 years old and off of warranty. They suggested checking the various forums.
These cabinets do not seem to have much intelligence built into them, so I am hopeful that the drives can be moved into a new cabinet without issue.