I'm going to have to hunt to find out about Michael. The only source I can find so far is Nigel Deacon's Diversity website. Michael wrote the following plays:
Fuller list on Nigel's site.
He died in 1991.
Jeremy Mortimer produced Headcrash. Jeremy is an experienced and well respected drama producer at the BBC where is has been Radio Drama Manager and is currently (2003) Executive producer, BBC Radio Drama. He's got an e-mail address at the Beeb, so again I'll try and get his comments.
Richard has done sound engineering/technical presentation on a number of BBC productions from the early 80s into the 90s, and maybe beyond. He assisted with the technical presentation of the BBC's excellent radio version of the Lord of the Rings.
Mia Soteriou did the soundtrack along with David Chilton. Unless there are two Mia's she's a busy lady appearing in lots of films and TV shows - usually in a musician role - as well as still doing music, currently for the Royal Shakespeare Company. Credits include:
She was also in Topsy Turvey and is currently doing the music for Ibsen's Brand with the RSC.
I'll see if I can get a photo and some recollections.
With regards to David Chilton he appears to have been (to still be) a BBC sound/music man with a number of mentions at the Diversity site (as has Mia).