Well, believe it or not, just this year I heard a much more gospel oriented version of Diamonds in the Rough done by a local group. I have been meaning to ask them what their source was, but keep forgetting to do so. Knowing them, I would suspect that it is straight out of some old hymnal, which may well be where the Carters got their version before they adapted it and made it their own. I also have been meaning to transcribe the words as they sing them. I will do so later, possibly even today.