Ed Komara in Gayle Dean Wardlow's (1998) Chasin' That Devil Music also suggests Leroy Carr's 'I Believe I'll make a Change' (1934), Josh White's 'I Believe I'll Make a Change' (1934), Jack Kelly's 'Believe I'll Go Back Home' (1933) and the Sparks Brothers 'I Believe I'll Make a Change' (1932) as precursors / influences on Johnson's song.

Robert Palmer (1981) notes in his Deep Blues:

"And hearing Arnold sing "I believe, I believe I'll dust my broom" on his next record, "Sagefield Woman Blues," must have inspired Johnson to invent his celebrated signature piece, "Dust My Broom." Even Robert's "Dust My Broom" guitar riff, a dramatic full-octave slide . . . seems to have been adapted from the more fluid, less agressive, but still recognizable bottleneck guitar fills on "Sagefiled Woman."" (pp114-115)

I have a copy of Sagefield Woman Blues somewhere (but not to hand), I'll try to transcribe the lyrics later, if no one beats me to it.

Brian