How can you tell if EQ Heads are from New Zealand Foundry

If they are still in the factory box and unopened it will have New Zealand printed on the box. I remember mine had it on there when I bought them a while back.

@Bobzilla is correct, the old style has a flat surface with the Part 318A or 318B stamped in the end.

If I can dig up a photo of mine when I got them I will post it later.