According to Sean O'Boyle's notes on "Bonny Portmore" ('The Irish Song Tradition', p. 50) the 'ornament tree' in the 3rd verse of John Moulden's text above (quoted from that given by F. J. Bigger), and 2nd of the 3 verses of O'Boyle's text, was the huge oak that was blown down in 1760. On the basis of this little bit of evidence "The Highlander's farewell to bonny port more" would be the earlier song.

I agree we need a new thread for these 'near Utopia' songs, with overlapping verses, but haven't the vaguest idea of what to call it. Steve Roud's folksong index gives the same number, #688, to "Come all you little streamers"/ "Green Mountain"/ "Strands of Magilligan"/ "Streams of Lovely Nancy". The latter is on a broadside of 1820-24 on the Bodley Ballads website, Harding B 28(29). The several American "Green Mountain" texts probably derive from the one in 'The Forget-me-not Songster', c 1850.

Broadwood and Fuller Maitland give a version called "Faithful Emma" in 'English County Songs', 1893, that, except for verse order, is practically the same as the untitled American one from 'An Astronomer's Wife' on my website. However, there's no Emma in the song, but an unfaithful Mary (untrue Polly in the American version) in the last verse, and they questioned whether that last verse belonged to a different song.