The Mystery of The Quotient has been solved. Research on the part of my friend Dave Lewis, He Who Knows Everything There Is To Know About Led Zeppelin, indicates that it was taken on February 3, 1975, at a post-concert party held by Atlantic Records at the Penn Plaza Club at New York’s Madison Square Garden. Evidently Andy Warhol, Keith Moon, William Burroughs and Amanda Lear were among those attending. Strange I don’t remember an encounter with Moonie as most such encounters were memorable to say the least.
The evidence to support this theory is that Jimmy wore the pearl necklace on stage that night and I would have been in NY at the time and definitely at the show and party, though I probably didn’t write about it in Melody Maker because I’d covered the opening of Led Zeppelin’s tour in Chicago at some length a week or two earlier, articles reproduced in the recent reissue of Physical Graffiti which I whinged about and copied into this piece on Just Backdated back in June: http://justbackdated.blogspot.co.uk/2015/06/led-zeppelin-physical-sour-grapes.html