Hi, Kiwi.
I have done a fair share of domestic and commercial metering in my time in mostly West Auckland and North Shore period (1991-2001).
In case of mains upgrades and new MCB panels, the meterbox had to be put outside to provide easy access to the meterreader and prefably on the South side of the house.
In cases when only the rewirable fuse panel was replaced with a MCB panel sometimes the inside meter remained or for a charge to the customer (± NZ 200)a remote dial meter 'was installed, called a 'handy meter 'or remote dial'.
Basically it is a ferraris disc meter, type S200.33 from Sangamo or an electronic meter Y120Ep (enermet) which drives a little dial which can be mounted outside on the wall or fence for easy reading.
These dials run of 12 or 24 volts supply pulses from the meter, so low voltage wiring can be used although its recommended to use screened cable to avoid radio interference.
It pays to check with the customers retailer what they allowe for. In the last couple of years electrical standards, POCO side have dropped, and they may allowe a panel upgrade to be done without meter box change.
