A lot of confusion comes from the later 60' early 70's period when Motown was operating on multiple fronts including LA and Detroit, it was very common to record versions of the most popular songs in different keys, tempos and feels for every different group and artist. Sadly I'm not sure there are any reliably accurate records for absolute confirmation. This also means that some bass lines attributed to Jamerson could have been played by Babbitt, Newton or some other session bassist Motown used over the years, remember Hitsville was at times running 24 hours a day and sometimes other regional studios were used to relieve the need for studio time.
