Yes, there are quite a few snippets of information on the web. There is also a short print run book (Snakes & Devils) but I'm not prepared to spend £200+ on a book!
Other interesting links:
http://goodmorningyesterday.blogspot.co.uk/2009/09/edward-williams-remembers-grand-prix-at.html
http://www.togoparts.com/forum/showthread.php?fid=6&tid=50727
http://www.early911sregistry.org/forums/archive/index.php/t-58766.html
http://www.motorsportmagazine.com/archive/article/october-2008/99/dancing-devil
http://www.motorsportmagazine.com/opinion/f1/forgotten-singapore-grands-prix
Other interesting links:
http://goodmorningyesterday.blogspot.co.uk/2009/09/edward-williams-remembers-grand-prix-at.html
http://www.togoparts.com/forum/showthread.php?fid=6&tid=50727
http://www.early911sregistry.org/forums/archive/index.php/t-58766.html
http://www.motorsportmagazine.com/archive/article/october-2008/99/dancing-devil
http://www.motorsportmagazine.com/opinion/f1/forgotten-singapore-grands-prix