Just an aside to this discussion that you might be interested in Lighter, considering your large collection of versions.

An Australian, Cecil Harry Winter (1883-1969), who later settled in New Zealand, claimed authorship of the original words of 'Mademoiselle from Armentieres' in a series of letters and articles in the newspaper Sydney Bulletin, some time after WWII.

He reckoned he'd composed them during WWI, though I'd know whether this was ever proved, either way. Being something of a balladeer, whose poems, usually published in newspaper under the name 'Riverina', it's possible. A few of these apparently entered the oral tradition in the Australiasian area. He was also a short-story writer on the side, so had a familiarity with 'fictionalising'...