In 1967 I "collected" a version of this song from a friend in Nova Scotia, then a young woman of about 25 or so.

The lyrics are slightly different from my friend's version. The tune is also slightly different (and I think better) than the one in Edith Fowke's article. Here are the words. She called the song

"My Jack I'll Wed Tonight"

A cowboy and his sweetheart stood beneath the starlight sky,
Tomorrow he was leaving for the lonesome prairie wide.
Says she, "I'll be your lovin' bride when you return someday."
He handed her a broken right and unto to her did say.

"You'll find upon this ring sweetheart my name ingraved in gold,
And I will keep the other half, it bears your name you know."

Three years have passed he did not come and I must wed tonight.
My father says we all will have a happy home so bright.
The lights were gaily glowing as they stood there side by side.
"Let's drink a toast to this young man and to his lovin' bride."

Just then there stood within the door a figure tall and slim.
A handsome cowboy was their guest and slowly he walked in.
"I'll drink a toast with you," said he and quickly in her glass
He dropped his half of the broken ring and anxiously he watched.

She tipped the glass up to her lips, the ring fell shining bright.
"It's you my cowboy sweetheart and my Jack I'll wed tonight."