An interesting read thanks Michael, I had heard about the Salmon Ponds trout hatchery and could remember some of the history.
I believe the rainbow trout story was similar, with the Auckland Acclimatisation Society receiving eggs from California in the 1800s, I don't know if these came via Tasmania as well.
Rainbows tend to be more difficult to establish and were not so widespread. From memory I think they did better in rivers that were connected to lakes, and I also seem to remember there being some sort of 'top up' hatchery in the North Island to ensure their future. ( but my memories are from the 1970s )
Cheers
Mike