Vaughan, what on earth makes you think I would know the year better than you!
Following links about her cancer the day her death was announced I did find a story where Cliff says that he met ON-J at a party when she was the girlfriend of Bruce Welch and how the two of them hit it off to become friends with ON-J and another girl going on a tour as backing singers and practical jokes being played on each other. The story ends with Cliff saying to be seen to be in a relationship with a women at that time would of been damaging to his career.
I can tell a tale about being in the same pub as George Harrison one evening when a couple walked in asking about him and nobody let on that he sitting in a corner of the bar supping a pint.
Opps, I just have!