I have to do more digging sometime into this, and would appreciate help from readers as well. ATTA Taxis was apparently an off-shoot from Wellington. All files on them are at Wellington’s office of Archives New Zealand, but according to a 1939 directory I now have, their Auckland office was at 32 Lorne Street, the Ngapuhi Chambers. A reader of the Avondale Historical Journal rang me today with information that ATTA stands for Any Time, To Anywhere.
Does this firm spark any memories?