Here is a link to Chapter 5 in Two Years in the Aviation Hall of Doom that covers the relevant issue about the Metro III. In fact, Max Hazelton had a Beech 1900 sitting in the Hawker hangar for over 8 months as they were trying to modify it to comply with the unique Australian rules. It was only when my Board approved the first of type from five countries that this aircraft was allowed to operate – and indeed, further improvements came in that allowed more people to fly, such as ETOPS.
Have a read and cry about the fact that we are now back where we were then in the Two Years in the Aviation Hall of Doom days. Just look at the recent CASA class G ARP or whatever it is now called.