Just listened to "The Swingin' Shepherd Blues" from the "Six Views of the Blues" CD - there is a bass line, but that's from the B3. Definitely. No mention of a bass player on this Cuscuna produced CD ....
I don't have "The Singles" LP any more, but I remember the version there to be identical. Seems Cuscuna corrected himself. The July 16, 1958 session on the CD was recorded with two drummers, Art Blakey on tracks 1-3, Donald Bailey on 4-6 - maybe the files were not clear thus leading to the assumption bassist Bailey was on the session. That bass sound clearly is no acoustic or electric bass but from the organ.