Just to throw my 10 cents in: I find a pretty close version playing in -EAEAE tuning (ie bottom string not needed). It’s pretty low tuning on the 4th and 5th strings but seems to work. The main riff is basically played by descending on frets 5,4,2 on the 5th and then 4th strings. On the YouTube video of Nic Jones playing live with his son at the Ryburn folk club, you can see him playing something like this (it’s around the 1hr20 mark).