With regards to the 'ghouls', see the quote from the report in my post of this thread #21. It tells us that the Prime Minister made a sweeping statement, based on poor evidence. Nothing changes then.
The M25 was built in sections from 1973 onwards. As far as I can recall and establish (Wikipedia), the Western section including the A30 intersection was one of the last in 1985. I was able to use it for a new job that I had just moved to. The whole ring opened in 1986.