Neither are songs I have previously heard but they do seem very similar. The arrangements make it difficult to pull out a specific melody line by ear JC's ABC Tunefinder found a single melody line for the Scottish song, but drew a blank on the shape note title.

The only web reference I found other than the Southern Harmony site was HERE in an Index which gives details of a book it appears in, but does not contain the actual book.

Let's face it many hymn tunes were written by the prolific composer Anon and most folk songs by his nemesis, Trad with words set by Tom, Dick and Harry. None of them worried whether somebody else had previously added completely different words.

Quack!
GtD.