At Ferrymead where there are already several rail heritage organisations based (CRS, Two Foot Railway, DTG, HVRC etc) there has also sprung up in recent years a "National Railway Museum of New Zealand".
The main problem it faces is being a private organisation rather than one that is supported by the government. If you are going to have a national museum it would have to be a state run body as this is the only way of getting past the parochialism that inevitably infests hobbyist outfits which characterises the majority of the rail heritage community in NZ. Of course there is nothing to stop anyone from calling themselves a "national museum" but politics will get in the way of any privately run outfit from being able to claim the same level of credibility as something that is run by the government.
There has been a change of leadership at NRM over the last few months and with that has come a realisation they will have to scale down the size of the project which has been going pretty slowly up to this point. Unfortunately doing this also means they risk that it becomes less of a "national" scale of operation and more on the level of most of the individual sites that are in other main centres.
The detail in the FRONZ newsletter highlights that most of the rail heritage organisations of NZ survive mainly on fundraising from charitable grant sources as their members are few in number and have only limited ability to spend on the projects that are undertaken.
A realistic view is that the project has been too ambitious and wide ranging with a lot of duplication of what is happening at other sites, including other groups at Ferrymead. In other words, they seem to have wanted to be everything possible at one site. The problem with this is pretty obvious, and that is that it will require enormous finances and other resources which are impossible to achieve. Ferrymead is already chockablock with way more stuff than any of the groups at it could ever possibly restore in the foreseeable or long term future, considering for example just one group, the CRS, has sheds full of stuff that haven't been touched in their 50 years of operation. The problem all museums face is keeping their collections within a manageable size and this can be contrasted with the mention in the same FRONZ newsletter of MOTAT's situation with 80% of their collection stored offsite. The risk then is that some of the stuff will deteriorate to the point where it is beyond restoration. Other stuff will never ever see the light of day.