Back on topic.  I've made a midi from the notation I mentioned earlier, which was at the website of the Metropolitan Community Church of Manchester.  They don't name a source for the arrangement, so I presume that it's from a hymn book.  Until it gets to the Mudcat Midi Pages,  it can be heard via the  South Riding Folk Network site:

When a Knight Won his Spurs  -melody line only.
When a Knight Won his Spurs  -with accompaniment.

There are two sets of The Fair Flower of Northumberland in the DT; this one:

Fair Flower of Northumberland  has several tunes with it (unfortunately with no indication as to where any of them came from) the first of which is a variant of the one I'm familiar with, and to which Jan Struther's verses were set.  Another of her hymns (set to the Irish tune Be Thou My Vision) may be seen in an earlier discussion here:

Lord of All Hopefulness

Malcolm