Have you listened to MJH's Library of Congress recordings? There's a LOT of songs on there!

While John Hurt was very much his own man, I find a lot of the "Piedmont style guitar" playing has similar qualities. I think there's a wikipedia entry on it. Essentially it's the folksier kind of style oft mentioned in the same breath as 'country blues'.

Singers/guitarists that have something in common with John Hurt might include:

Elizabeth 'Libba' Cotten (classics like 'Freight Train')
Archie Edwards (his Blues N Bones album is beautiful)
Mance Lipscomb (treasure trove of song after song)
Pink Anderson (voice like syrup, lovely sense of humour)
Brownie McGee (his solo albums on the Folkways label in particular, songs like 'Face In The Crowd', which I vastly prefer to his better-known stuff with harmonica player Sonny Terry)
John Dee Holeman
Clifford Gibson (some very oddly poetic lyrics)
Buddy Moss (again, some very idiosyncratic blues songwriting)
Etta Baker
Robert Belfour (though maybe a bit harder-edged than MJH)
Jimmy 'Duck' Holmes

and even white country-blues/folk singers like Roy Bookbinder and Tom Paley

You might even wish to investigate players like Blind Lemon Jefferson, Rev Gary Davis and Blind Blake, but that's a rather more complex style, bit more ragtime and intricate