I teach this tune in my upcoming Lesson Load Volume 9 https://www.daddystovepipe.com/guitar-lesson-pack-tabs-volume-9.php
This song was orininally recorded by Mississippi John Hurt (in standard tuning key of C); my variation is based upon the playing of Mike Dowling.
It’s in open D tuning with a capo on the 2nd fret, leading to open E tuning.
I’m utilizing a “Delta Resonator Guitar”, made by John Alderson of the UK