As missing person enquiries go, this has gone on for decades now. There was talk about her being buried at an old Army Barracks site in Telford that has since been redeveloped for housing, a Royal Marine Camp in the Southwest has also been mentioned. However, a very plausible witness account came from a lorry driver who was walking along the towpath of the Grand Union, Brentford at around 5 am one morning not long after she went missing, he witnessed a man with a trolley loaded with a suitcase who kept his head down as he passed, a few minutes later he heard a large splash behind him, the man looked like John Cannan who is currently in prison serving life for murder.
This information was given to the MET Police at the time but was never followed up. The witness retold this story to a friend many years later just before he passed away, his friend went to the police after her friend's death as she had made a promise that she would try and do something about it, however, the Met Police has point blankly refused to undertake a search because they say since then they have had police divers holding a training session in the vicinity and likewise so has the London Fire Brigade. One of the original detectives on the case is furious as he believes the canal should be searched properly.
The location has been described as the Grand Union Canal running through Brentford the GUC doesn't run through Brentford that I can see as it becomes the River Brent, so if this is correct and the body was dumped in the River Brent then it could have been moved by underwater river currents. Especially if the body was removed from the case beforehand as per Cannan's MO.
I haven't yet dowsed this one but my intuition tells me this canalised river is more than likely where she is.