Spitoon -you are wrong. Southend was not renamed to London Southend in the AIP a few years ago. All that happened was that to increase functionality of the document,AIS put an extra cross reference in for Southend under 'London Southend' under the airfields entry list because so many people know the airport as 'London Southend' after it was renamed that in the early 1990's. The AIP entry itself remained as Southend.
I believe pressure was then brought to bear to remove the extra link.
The CAA would seem to agree that Southend is a London area airport - look at the airport statistics page on the ERG pages.