This may be a tough one, but I learned it as a kid from a Regal Zonophone 78. It was 1930's cowboyish in style with country male harmonies.

The chorus went something like "...we promised to love one another, learning the sweet Golden Rule, .......... back in the old Sunday school.

I have no real idea whether it was of US or Australian origin, but they also sang Ragtime Cowboy Joe.

TGIF John