Super Sports Number 6?
Unique Cars - Story by Graham Smith Photographs by Peter Watkins/Slit Image
Source: February 2002 edition of Unique Cars (pages 44-47)
An article on this Super Sports Seven belonging to Barry Ryle in West Australia was featured in the February 2002 edition of Unique Cars (pages 44-47). The car is reportedly the 6th factory Super Sports produced. I can not reproduce this article for obvious copywrite reasons but I believe Unique Cars is available in the UK.
The Austin Seven Motoring Pages