Some NZ buttons queries

[GTB]

Would very much like to have more information on these buttons, especially dating if poss:
1. New Zealand Forces, 17mm: dark brown chocolate plastic, integral moulded 'bird-cage' type shank. When worn and on what uniform?
2. Ditto, 25mm: bronze (centre flattened). Date of use, by whom and what uniform?
3. N.Z. Staff Corps, 17mm: I have a date for this Corps as 1911-47, but does 1t apply to this design? Was there another button when the Corps wore the Fern badge? As this unit was a relatively small one (composed mainly of Staff Officers), is the button scarce?
4. N.Z. Army Ordnance Corps, 17mm: I am confused as to whether button pertains to period 1923-47 or earlier. If not earlier, can anyone show me preceding buttons for this Corps?
5. New Zealand Forces (Artillery), 17mm: is this design for Volunteers, Regt of NZ Artillery, or Royal NZ Artillery? Period of use of this design?

Apologies for blurred images

All comments most welcome
GTB

[Tinto]

Hi GTB,
I'll answer to the best of my ability.

1. New Zealand Forces, pattern dates from 1911
This "plastic" button most likely WW2 vintage, often worn on greatcoat

2. New Zealand Forces, pattern dates from 1911
This bronze button could be WW1 vintage, worn by officers on tunic and greatcoat

3. New Zealand Staff Corps, dates from 1911, not sure when became obsolete. Not a rare button.
(New Zealand Permanent Staff 1921- has kiwi in centre of Maltese Cross)

4. New Zealand Ordnance Corps, 1917- The earlier button(1915) has similar shield with scroll inscription "Army Ordnance Department"

5. New Zealand Field Artillery and New Zealand Garrison Artillery, dates from 1911. Some NZ Artillery Volunteer units wore their unique buttons, or the general pattern (Crown over gun, no inscription)
There was also a Territorial Artillery button, same as your button but with "Territorial" in place of "Forces".

Hope this helps,
Tinto

[GTB]

Thanks once again, Tinto, for your assistance. You've been most helpful.
GTB