Hi Tony,

This is [approximately] the chorus that Hamish sang to me, in around 1970.

I didn't raise my son to be a soldier
I brought him up to be my pride and joy
Who dares to put a musket on his shoulder
To shoot another mother's darling boy
Why should he fight in someone else's quarrels
It's time to throw the sword and gun away
There would be no war today
If the nations all would say
No I didn't raise my son to be a soldier

He knew only this, and wanted more verses, I talked about the Little England - as opposed to Great Britain - protesters in Britain about the Boer Wars, and I wrote verses that aimed to reflect that time and the appropriate references.
Later I learned from a book by Tony Palmer on Popular Music that the original song makers in 1917 with the US entry into WW1 rewrote their song to be I'm Glad My Son Grew Up To Be A Soldier.
Professional songwriters, eh?
Re the tune - need to check that and come back to you.
Ewan