FDF/anothertyke
I'm not young but not old enough to remember the debate that well.
Regarding it being a third London airport and not a LHR replacement I'm not sure anyone would have envisaged the huge growth in air travel that we take for granted now. In those days a holiday for my family was a week on the south coast. My late father had mixed views about the issue. He realised that had the plan gone ahead it would have meant the destruction of a lovely part of rural Bucks. However, as an aviation tech author he would have had no problem finding work.
Wing/Cublington are indeed next to each other! Wasn't the pressure group against the scheme called W.A.R.A or something similar.
Edited to add:
History - London's Third Airport
It was Wing Airport Resistance Association. Power of google!