The SMLE Mk I rifles were only issued to the Otago Rifle Volunteers which had a strength of 12 companies of Mounted Rifles and 28 Infantry companies, all based at different areas throughout the province. The number would be a rack number followed by the unit number. Unfortunately I have not found any existing records that would identify the unit number.
That does not really fit with examples seen, they are nearly all inventory number over 05 with a small number with the inventory number over numbers in the mid/high 20s what happened to all the 01, 02, 03, 04, 06, 07........etc rifles if these were unit numbers?