To the best of my knowledge, they're two different songs: Flowers of the Forest is a traditional Scottish folk song, whereas No Man's Land is a modern folk song written by Eric Bogle which contains references to Flowers of the Flowers.

The Men They Couldn't Hang... that takes me back. I had a tape of some of their stuff that I'd copied from a cassette I'd borrowed from the library. So they never sold anything to me either.