Help with Victorian Crown ER Button identification

[Corey]

Hello from New Zealand

I have been searching for such a long time to find out where this button fits in...
And if it could be part of any New Zealand Volunteer units
that seved here at that time.

I first found the button long ago at a car boot sale in a bag of military buttons.
Then just this weekend I popped into a local antique shop and had a rummage in a box of buttons and found a bunch of white metal Volunteer Artillery buttons and also what I think is a small brass General services corps Volunteers, all with the Victorian crowns.
But to my surprise in amongst the lot was another brass Vic Crown ER .
So now I have two of these mystery button's


Can anybody please let me know what they are.

All I have found is the maker
Smith & Wright Ltd, the limited added 1888-1889.
With the crown obviously changing 1901.
So that's my time frame

I have also only recently found this exact button in a NZ volunteer button collection with the description ER?.
Sadly the owner of that collection has passed away .

Thanks for taking the time to read.
Any help appreciated.

Cheers
Corey