True, to sing an "old relic" is sometimes not received well by some audiences. However, when it is seasoned with a modicum of modernization, it often becomes quite palatable to the tastes of many. I have found it to be as true with cooking with the use of old recipes. While granny's use of gobs of lard was quite suitable during her time, current trends make the use of it almost unthinkable.At the same time, presenting the modernized version of the old recipe in a manner which produces an atmosphere of almost certain enjoyment. The checkered tablecloth does make a difference.
Yes, there are venues for singing "museum pieces". And the seeking out of the supposedly "original" version of a song is both challenging and intriguing. But most of the folk music we play, even the real oldies, are the results of evolution of some degree of evolution. I think the hard part, as Joe points out, is deciding for yourself where to place the balance between modernization and historical accuracy.
After all, you want it to taste like granny's apple pie; but your current thinking about chlorestoral makes you want to adjust the recipe a little. Who is to say if it tastes just as good as you remember it? Your granny's granny probably made it a little differently too. But they weren't into writing down recipes in those days.