Matches the description in Hood's book except for the "woody" bit. It looks to me that it's more leathery than woody. There are other Perenniporia species in NZ but they don't match the description.
Grey Smith
2018-02-00
2018/02/03 4:24 PM NZDT
New Zealand, Manawatu-Wanganui, Manawatu Gorge, Ashhurst, New Zealand
Growing on the side of a small log in broadleaf-podocarp forest. Woody brackets to 32 mm across, upper surface uneven with grooves and bumps, brown fading to fawn then white at the margin. Lower surface white with large pores (3 per mm).