I suppose we could add to the mix (I don't know why I didn't earlier) the mysterious "Essequibo River" song. I say "mysterious" because, unless I'm blanking, I don't remember ever seeing any record of it other than in Hugill's SfSS. Hugill learned it from Harding, along with "John Kanaka."

The shape of John Kanaka and Essequibo River has some similarity.

Both have (at least as Hugill renders them) the sort of "extra" 4-measure shout appended to the typical 8-measure chanty form.

(I actually don't consider this as something extra; forced to guess, I think this is a variation on the soloist's part that one can intermittently perform. Nevertheless, it stands out in "Kanaka," "Essequibo," "Do Let Me Lone" [A Guyanese song, again from Harding] and the very similar "John, Come Tell Us as We Haul Away.")

Both have a stream of nonsense-y words as their chorus, and the choruses are the same every time (rather than alternating in tune and/or text like "Way hey, Blow the Man down / Give me some time to blow the man down").

The "Essequibo" chorus is,

Buddy tanna na, we are somebody O!

The melodic contours of the choruses of "Kanaka," "Essequibo," and "Old Aunt Jemima" are also very similar.