Hi Lindsey, SpitfireTripple and JD,
While I have to accept JD's excellent piece of reverse engineering to show us exactly how his sample was attached, on further cogitation I have to admit that I think there is more here than meets the eye.
Today, web shops are full of Hei Toki style lashings on decorative stone / bone etc. ornaments, and they all tend to follow a similar trend - the ornament is heavily 'relieved' to hold the ornamental binding, and they all tend to have a necklace style similar to the one JD opened up for us.
Unfortunately, I have found it impossible to locate any of the Hei Toki images that I accessed four years ago, I think they were mostly museum pieces of this very old art form. However, from recollection, their termination to the necklace started with a wrapped section rather than going straight into the necklace as today's samples do.
Back in 2006, I tied my first attempts at this binding and was amazed at the tension and grip the binding built up as the binding was progressively applied. It wasn't until two years later that I realised / discovered how the binding achieved this ferocious grip

I tied the binding with only small shoulders on the 'ornament' and without any necklace hole - no secrets, nothing hidden. The nature of the binding was such that any tension on the necklace simply amplified the grip of the binding on its mount. Later, when I realised how the binding achieves this, I understood how this beautiful binding is also a testament to the Māori skill at fusing form, function and beauty into the same work - indeed -
'Beauty had nothing to hide...' - a veritable Godiva of a binding, much like our very own Anglo Saxon beauty who demonstrated much strength without hiding anything...
So, although JD has demonstrated that modern jewellery uses hidden holes, I have to admit that I remain unconvinced that the creators of this fixing used such contrivances when the power of this binding is such that it does not need any such contrivance - it has strength, power and beauty all with transparent simplicity. For me, that feels much more in line with the principles of 'Nation' than the wearing of an ornamental dressing to hide the reality of a simple (even if beautifully formed) hole.
Derek