Mr Kay quipped that having his work chosen for the superstars was a case of "local old boy makes good," but bone carvings made by him and wife Candy Kay have been selling for more than 20 years. His intricate, detailed carvings are in galleries in France, Japan, USA and Australia as well as represented online at Bone Art Place.
The tennis stars' gifts might lead to more high profile commissions but Mr Kay is busy enough keeping up with demand.
"I've slowed down a little bit these days but I'm out here working most days," he said of his backyard studio in Tikipunga. Before retiring he sold bulldozers and other heavy machinery.
His grandmother was "full-blooded Ngapuhi" and his grandfather "full-blooded Irish", and while he likes to explore Maori and Celtic symbolism he is sensitive to many cultural motifs, including his USA-born wife Candy's Sioux roots.
He started out using beef bones before switching to the "cleaner" deer bone. The bone stubs drop off the deer after they shed their antlers and a new set begins to grow so no animals are hurt in the making of Mr Kay's art.
A tumble of tusks, skulls, horns, antlers and jawbones overflows from one cabinet. In another cabinet full of intricate completed treasures sits a fishhook carved from mammoth bone - as is the taonga hanging around Mr Kay's neck. Mrs Kay's sister lives in Alaska where the mammoth bone would occasionally come to light. "It's getting harder to get hold of these days," she said.
Deer bone is a sustainable resource, and in the hands of a master carver, luminously beautiful - although a stubborn piece of bone can be frustrating, Mr Kay said. "It can fight you to the very end." That's a fitting quality in gifts made especially for two of the world's toughest tennis players.
