West Auckland Historical Society proudly have this in their collection -- a souvenir plate from the reopening of the New Lynn Train Station last year. (Does this really promise they'll have movies back at New Lynn some time? That would be good.)
Meantime, during work currently underway to enlarge the Society's display annexe, local historian Ben Copedo spotted this shard in the clay, and fished it out. He'd love to know what it's from. The two photos are the same fragment, decorated on both sides.
If anyone can help, please let me know, and I'll forward the answer to Ben.