This may be a long shot, but has anyone got / would anyone be able to transcribe the two-part arrangement sung by Shirley Collins and Heather Wood on the Young Tradition album The Holly Bears the Crown? The tune is close to some of the sheet music I've seen, but not quite identical. In ABC the first line of the melody goes something like this:

X:1
K:F
M:3/4
L:1/8
G2|GABAGF|GA B3 G|AB c2 F2|G4

and the first line of the harmony part

X:1
K:F
M:3/4
L:1/8
F2|E2D2F2|E2D3G|F2E2D2|C4

After that it gets complicated...

Anyone know/recognise this version of the tune?