Well age and senility and perhaps just general stupidity strikes again.
Turns out that when I tried to copy the Scientific American files I was most recently working on to the Flash Drive I was preparing to send out I made a small error.
I had already copied them on a few days before into the Directory I put on outgoing drives to hold files in progress… and completely forgot I did so.
Normally that would not be an issue except that the Scientific American files are in the neighborhood of 30gb. So not without those files the Flash Drives still had about 50gb of free space. Plenty to hold a copy of the Scientific American files with a good bit of space left over.
Once I deleted the duplicate directories there is plenty of space for the foreseeable future expansion.
So an unnecessary exercise. Still nice to have the feedback so that when it DOES become an issue in the future I have some idea where to head.