A real nice field recoring (Cummins State Farm, Gould, Ark. 1934 Kelly Pace & gang) of this is in the the Library of Congress, archive of Folk Culture. Rounder released it on CD called 'Negro Work Songs & Calls'. It a little bit different from Leadbelly's version & worth the time & effort to listen to.
Sorry, can't give you anything on the intro you're looking for.
Barry