Of all the stories (which also include an event that took place in a bar on tour in Ireland or the Isle Of Man - I can't remember which at the moment), the Prestwich one is the one that has usually been accepted because it fits in most with the timing of the song and so on.
It was definitely sung pre-Div 2 (I referred to it in one of my books published before relegation), but it became popular during the Div 2 days.
In 1994 I wrote a piece for the Kippax Last Stand which included chants/songs and I didn't mention it at all which suggests that it wasn't widely heard at that time, but that doesn't mean it hadn't been sung of course.