I found this release with very little info in MB. It was added to MB way back in 2002:
Release “The Sons of the Pioneers (disc 4)” by Sons of the Pioneers - MusicBrainz
I found a release on Discogs, a 4-disc compilation.
https://musicbrainz.org/release/20dff2c2-bde3-4e26-abc6-79f63a5e6d6d
Disc 4 of this compilation is a perfect match for the track list of the “(disc 4)” release above.
I have been unable to find individual entries for the other 3 discs in the set, so I thought I could import the set from Discogs, then merge the incomplete disc with the 4th medium in the set. But, I found out that merge doesn’t work that way. So, should I just enter an edit to remove the incomplete release? There’s very little info in it beyond the track list.