Hi Mick,
I think pins came in early 90's. Maybe for Old Comrades Association.
Wouldn't make sense for a unit that wears the RNZAC badge on their berets. Besides, they aren't in the Order of Battle anymore, the new flavour,(Territorial) is the 4th Waikato Mounted Rifles.
NZ re-org after re-org
I'll keep an eye out.
Clay