Seemingly unprovoked software corruption on external drive. Can I salvage?

I have an external disk on my Mojave system that seemingly had the volume name overwritten with another volume's name and now it won't mount and Disk Utility firstaid won't help. I have an external enclosure containing two SATA drives I also have a "toaster" for dropping in other drives I have on my shelf. In the enclosure I have volumes "Drone Raw" and "Masters" - both mounted. I pulled an older drive off the shelf also called "Masters" and dropped into the toaster. It mounted fine and I had two "Masters". I've done this before without incident. Then something went awry and I am not exactly sure of the sequence. I think I unmounted the "Masters" in the enclosure. Maybe both. I can't be sure how I got here. But suddenly the Masters in the enclosure would not mount up at all. When I used Disk Utility, it thinks that the volume name is now "Drone Raw" and it won't mount. The true "Drone Raw" mounts fine. If I try to mount Masters, it then shows two Drone Raw with one of them being unmounted. The results of a First aid read: "Repairing file system. Volume is already unmounted. Performing fsck_hfs -fy -x /dev/rdisk6s2 Checking Journaled HFS Plus volume. Checking extents overflow file. Checking catalog file. Invalid sibling link Rebuilding catalog B-tree. The volume Drone Raw could not be repaired. File system check exit code is 8. Restoring the original state found as unmounted. File system verify or repair failed. Operation failed…" I tried command line fsck_hfs -r and -f to no avail. Is this drive hopelessly scrozzed? If so, more academically, why did this happen? I really wasn't doing anything creative or risky at the time. Thanks for any help Bill