Got another enclosure with backwards compatibility to USB 2.0, and it worked. Let FLEX initialize it, and then took it to my Ubuntu box to rsync the old volume to the new volume.
That is in progress as I type (a gig takes a while). I will edit this reply when it completes and I am hopefully able to remount the new volume on the FLEX and it sees and can play my prior recordings.
Update: copy complete, volume remounted on FLEX, all is good. Thank you for the help and support.
