For folks wanting to break up the 222 tracks into the separate albums, note that each .flac has a tag "#" (actually a VORBIS_COMMENT named TRACKNUMBER) which gives the track number within the full archives (Windows Explorer will show these). Also, the track names are all unique except for 3:
Distinct versions of Motorcycle Mama occur in both the Neil Young and Neil Young, Nicolette Larson folders
Distinct versions of Soul of a Woman occur in both the International Harvesters and Trans Band folders
Distinct versions of Southern Pacific occur in both the International Harvesters and Crazy Horse folders
For Plex you can rename the three duplicated files above to unique names, then put all tracks into one folder, then open that folder in PerfectTUNES ID Tags or MP3Tags and sort on the Track column. You can then pull out your 17 CDs or list of songs by CD, and modify the Disc tag on each track to put each song into the disc on which it occurs.
This is way more painful than it should be, but it's much faster than sorting by hand.