I have plenty of happy hours in SKJ & SKW when they were Skytrans; BUY was originally Vic Polair IIRC, then bought by Qld Ambulance for the Bundy base (ergo 'BUY'), went to RFDSQLD as a spare when they took over the air ambulance gig before being sold to a Darwin operator. These were 3 of the nicest, best equipped 404s in Aus, sad to see them ending up like this.
If my memory serves me right BUY was being used by Northern Air Charter in mid 2005. I'm not sure who actually owned it at the time but do remember it spent a great deal of time in Matt Overell's hangar.
Regards,
OpsN.