Banks of the Mossen is just a garbled version of 'Beautiful Nancy II'
Roud 1646. If I remember rightly it now has the correct number in the Index, not 1201. It is a Vauxhall Pleasure Garden piece like many similar folk songs, and appeared in 'Cupid's Magazine' of late 18th century among other publications of the time. It has the tile 'Beautiful Nancy II' because there is another 'Beautiful Nancy' Roud 18525.