CUJimmy, I cannot quite decide what it is you want to find. Having heard quite a lot of field recordings of "the old singers" from my part of the world (rural southern England), I have almost always been disappointed. These were, of necessity, recorded when the singers were very old. This doesn't help my 20th century ear to appreciate their craft.
I wouldn't want to sing like that myself - it would be untrue to them, since I didn't endure their hardships and deprivations, untrue to the local dialects, which have disappeared since I was a boy, and untrue to those still around and old enough to recognize authentic dialect. It would also be untrue to my own singing abilities, such as they are.
The greatest disrespect I can pay to them is to present their songs in my half-understood pastiche, to an audience that has no better understanding than my own. So I don't do it.
This sounds like a very "anti" point of view, but it is most certainly NOT the case. I DO sing the old songs, but I don't put on an accent, neither (mainly) did Ewan McColl. (I am trying to restrict myself to your end of the world) Ewan had a unique talent. A close Scots mate of mine (who taught me to play the tin whistle) says this: "Ewan McColl just sort of sits on your shoulder". He is right. Choose songs that you can identify with personally, sing them as you feel them, and at least you will know that your heart is true.
You've had lots of good advice about source singers; the main thing about singing is to tell your audience in song how you feel.
My favourite expat song is "From Clare to Here". It wasn't written by an Irishman, but just try saying that in Islington! (It's in London).
Kindest regards, with the fond hope that this is helpful,