The IRA rather than RHA version of The Merry Ploughboy has much the same kind of pattern, but it's "I'm off to Dublin in the green, in the green, where the helmets glisten in the sun, where the rifles clash and the cannons flash to the rattle of a Thompson gun", or words to that effect. Old grey mare etc are standard issue, notwithstanding whichever army you choose to volunteer to.

Then there's another Merry Ploughboy which starts:

The lark in the morning, she rises from her nest
And she goes home in the evening with the dew all on her breast.
And like a merry ploughboy she whistles and she sings
She goes home in the evening with the dew all on her wings.