Susanne's "Plains of Waterloo" (with a few minor variations - sixteenth of June instead of 14th, for example) is included in an excellent book called "The Cruel Wars - 100 Soldiers' Songs from Agincourt to Ulster" compiled by Karl Dallas (also known at one time as Fred Dallas, and writer of a lot of good songs, including Thew Family of Man), which was published by Wolfe Publishing in London in 1971 or so.

And he credits it to O.J.Abbott of Ottowa (sic) - and recommends the Shirley Collins recording.