Good problem, Kristine.
I'm doing research about some folk songs of soldiers' everyday life in field and barracks. It is astonishing how many versions I found for mostly every song I wanted to refer to in my work, in lyrics and in tunes over the centuries.
So I have my experience: A real living song varies in time, dependent of who heard it, remembered it incorrectly, or changed the words fitting a new time: I think you will never find an authentic version, only a version written down at a certain place in a certain time, with different versions elsewhere, only unrecorded.
One of my favourite songs came in three slightly variated tunes; I harmonized them to my private gusto. But as we continentals are lisping: De gushtibush non esht dishputandum.
So change what you want; the audience will decide with applause or foul eggs and tomatoes.

Wilfried