Hank Williams is making a buck pitching a snake-oil cure-all to the gullible, capping his spiel by picking up his guitar and singing. In the crowd is The Drifting Cowboys, a group of touring country-western musicians who happen to be passing through. Say, Hank, would you like to join our group? Memphis-born George Hamilton is winningly natural as Williams in the musical biopic of the short-lived but forever influential “Hillbilly Shakespeare.” It’s a deeply felt, lived-in story, made with the assistance of his widow Audrey and featuring timeless songs (Long Gone Lonesome Blues, I Can’t Help It and Hey, Good Lookin’ among them) lip-synched by Hamilton but sung by another C&W great: Hank Williams, Jr.