

Jim Brodie wrote about them in Volume 6 of the RPSNZ handbook series The Postage Stamps of New Zealand (1977).
He described the ongoing issues with a prepaid-by-stamp system, which started a decline in 1928 when the 25% surcharge for pay on arrival parcels was removed, meaning the advantage of prepayment by stamps was largely removed.
By 1940 use of the stamps was limited. In 1951 a new parcels system was introduced and all the stamps were dropped except ones for Newspapers, and those finished in 1959.
So what are these? They are labels showing prepayment of Railways Charges, for affixing to the parcel, or parcel label.




They're all the same stationery number P.L. 10, but all different in some respects other than the depot name.
No idea of the date, but I'd assume from the period when the stamps were in decline.
Are they railway stamps worthy of cataloguing alongside their more colourful and perforated cousins? I think so.
Adam.