I remember hearing that Brian had nothing to do with the SB that eventually made it on the Light Album but that it's an exact duplication of a track produced by him.
Well I doubt that, since aspects of the "L.A." version's track sheet (notations designating guitar tracks as "Billy" and "Chuck") match up to names listed on AFM contract from the Brian-produced early '78 Brother Studio session (and the personal recollections of guitarist Chuck "Crane" Kirkpatrick, who vividly recalls Brian being at the session he was on).
Vocally, though, it could well be another story.