I think part of what wasn't working for me was the regularity of the tune as Shirley Collins sang it (which is part of what makes it work so well with Dolly C.'s accompaniment) - and in particular all the times one syllable is split into two quavers, so that
It stru- ck hi- m with sur- prise
effectively comes out as nine syllables.

Slightly simplified version that I'm currently working on:

X:3
T:Lord Allenwater
M:4/4
Q:1/4=100
L:1/4
K:G
z/D/|GGGB|A/G/ED3/2G/|Acdc/B/|
A2z3/2G/|Acdd|d/c/AG3/2A/|
ABAG/E/|D2z/|

I've also managed to track down the Within sound version - totally different! There's a world of music out there.