Two months just doesn't seem long enough to add a new type to their AOC, especially a Dash 8. Check & Training, maintenance, cabin crew, ground handling etc are all a big step up from a 1900.
What about a current Dash 8 operator flying a couple on behalf of West Wing?
My guess would be Maroomba, given there's a couple aircraft sitting in Cairns now that we're probabily on their AOC only six months ago. That would make the two month timeframe a lot more achievable.