There has never been a professional production of THE MYSTERY OF EDWIN DROOD in Australia. I do believe that a community theatre group (in Sydney?) did it some years ago and a recording was made.(Self funded). This is probably the CD you are refering to. Unless you are a big fan of the show I'd be inclined to steer clear of it.
Being a huge fan of Drood I sought out this recording after learning of its existance several years ago. The recording itself is a mixed bag of mediocrity. While it was fascinating to hear the alterations to the score that were made in the post-Broadway productions (the tour and what is now licensed regionally and to amateur groups) such as 'A British Subject' replacing Ceylon and a different version of 'Puffer's Revelation', the recording does sound very amateur. Rupert Holmes is listed as a supervisor for the album so clearly he condoned it on some level. It has 30 tracks and features 5 versions of 'Out on a Limerick' (Helena, Rosa, Bazzard, Crisparkle, Neville) and all the possible Murderer's Confessions.
This production was done entirely with Midi technology. The score is completely synthesized and sounds rather tinny and odd at times as a result. If you're a fan of the show, it's fun to hear another take on it but most people would find it's reduced synth orchestrations and amateur performances (the voices range from pleasant to painful) hard to listen to. This album was released through an Australian label in 1994 and was originally presented by Phoenix Theatre Productions, a non-professional theatre company in Sydney.