Except for the Percy Mayfield verse, all the citations by Jim appear to have these same pattern (fit the tune) that John Handcox used. So it seems likely that Handcox borrowed a tune and refrain that was already floating around. The World War I verse may have come about the same way. Bruce Phillips: "They took the hymns because they had the prettiest tunes, and changed the words so they made more sense."

I wish I had the resources to check the origins further.