I'm fairly certain it was 1970 as my first baby was very young and the second was born in 1973. We left Cullingworth shortly after for Dronfield. It's odd what you remember but I distincly remember it was the first night he slept through! I notice there were gaps around early 1970 though.
My recollections of just who was on are very hazy now but I do remember that every time the Topic moved, which was often in those days, it always seemed to be Keith Marsden (with Brian Senior I think) who opened in the new venue.