Uploaded this afternoon by RadioJinglesonline.com,

30 minute documentary with Tony Blackburn interviewing Crispian St. John and Mike Barrington at Radio Sovereign and Dave Stevens at Radio Jackie.

1983 documentary which was repeated in 1985.

https://soundcloud.com/radiojinglesonline/bbc-radio-london-the-london-pirates-documentary-with-tony-blackburn-1985

Two webpages on Radio Sovereign on Bob Le Roi's website. I remember ringing them up when I heard them in North Hertfordshire, had a 10 minute chat with Crispian St.John.

http://www.bobleroi.co.uk/ScrapBook/Sovereign_UK/Sovereign_UK.html