"Snatch It Back and Hold It" is indeed the correct title of a song by Junior Wells.

It was recorded by Junior Wells on "Hoodoo Man Blues," 1965; by Aron Burton on "Aron Burton Live," 1996; and by James Solberg on "See That My Grave is Kept Clean," 1995.

Junior Wells' recording is also on the compilation album, "40th Anniversary Blues," 1993; on the Laserlight compilation CD "Midnight Blues," 1994; on the 5-CD Laserlight compilation "Blues Box," 1994.

All this information comes from AMG.

CDNOW has a sound sample, but these are the only lyrics I heard there:

"Everybody tells me, I'm not doing too bad, baby.
You know I ain't got no brand-new bag."