I believe I may have cracked the earliest NZAOC badge riddle, well it certainly predates the supposedly 1915 dated picture of Colonel A H Herbert.
The following photo is from the National Army Museum of New Zealand, it shows members of the New Zealand Supply Depot Staff at Zeitoun Camp, and was definitely taken in 1915, the majority of the cap badges displayed are Army Service Corps
However the chap in the front row third from left is definitely wearing a British Army Ordnance Corps cap badge on his lemon squeezer and NZASC collar badges.
