answered my own questions looking through the DT. I've now got four different songs. Hope I didn't/don't add to the confusion here.

1. Didn't find "Soldier John" in the DT.

2. Found "Soldier, Soldier" and it's a different melody, but almost identical lyrics in the verses.

3. Found "Nightingale" - a different melody but similar lyrics to the ballad I learned.

4. I think "Brave Grenadier" is the name of the ballad but didn't find the right one in the DT.

So, now I have four different tunes mushing in my head!!