It's a "pretty piece of paper" that represented a life-changing sum of money when it rolled off the printing press 150 years ago, was owned by one of New Zealand's early bankers, and would later change hands at auction for almost $100,000.
When money dealer Joshua Lee added the BNZ £100 printer's proof specimen to his collection this year, it was initially with the plan of flipping it for profit.
But the 20-year-old, who last year turned his hobby of collecting coins and banknotes into the small business Aventine Numismatics, realised he couldn't yet part with his new addition.
"I've found myself reluctant to list it. The reality is I do have to consider one day if I need to sell. I'm in business so I can't keep everything - if I was a millionaire I'd keep it forever.
"It's my favourite item in my collection so far. It's irreplaceable, and it's quite likely I'll never see something like this again."
Before the Reserve Bank was established in 1934 and began printing its own banknotes, trading banks created their own, including BNZ's third issue £100 banknote issued between 1873 and 1899.
The banknote was printed in black on a white background, with its denomination across a brown panel in the centre, and with two medallions showing scenes including Māori, a steaming volcano and kiwi.
It was the highest denomination issued in New Zealand, Lee said, with a face value equivalent to about $15,000 in 2022, according to the Reserve Bank's inflation calculator.
At the time it was issued the average wage for a kauri digger was about £2 a week ($312 in 2022), while a jeweller could expect to make about £3 a week ($469). A six-room Auckland house cost £31 to £46 a year to rent ($4800-$7000).
Lee's specimen banknote was never in circulation, instead among those printed for banks worldwide to check any BNZ £100 banknotes presented to them were genuine.
It was previously owned by Falconer Larkworthy, a high-profile figure in New Zealand's economic development who helped BNZ compete for goldfields business after the bank was established in 1861, and later managed BNZ's London base.
Larkworthy may have acquired the specimen banknotes while visiting the bank's printers, or been given it as a keepsake, New Zealand coin and banknote author and expert Rob Pepping said.
Banknotes were preferred currency in the Otago goldfields, where theft was a problem, Pepping said.
"Miners didn't like sovereigns (coins). They liked banknotes because they could fold them up and hide them on their person. And £100 was a huge amount of money in those days."
Lee doesn't know how the banknote specimen came to leave Larkworthy or his descendants' possession, but its history included a staggering AU$85,000 (NZ$94,000) sale by the Rare Coin Company in 2013.
He wouldn't say how much he paid for the banknote specimen, but if he did one day sell he didn't expect to snare a sale price to the 2013 transaction, which came at a time when there was high demand for collectible New Zealand and Australian coins and banknotes.
There were eight BNZ £100 specimens like Lee's known to be existence while only one previously circulating BNZ £100 banknote remained in private hands, along with about 50 of the banknotes kept by the Reserve Bank, Pepping said.
Because of the notes' face value, the original owners didn't save them - the sole note in private ownership had been found inside a piece of furniture in the 1970s or 1980s.
"It wasn't something people would put in their Bible and not use. It was just worth so much … it would've bought you a house."
In 2022, the specimen now in Lee's collection likely won't get him a house.
But it might be a decent chunk of a house deposit - if he can bring himself to click list on an auction website.
"A few people have said, 'you're only 20, you need the money, sell it'. But I can't."
Until he's ready to sell, Lee's enjoying poking into the note's history - of which much remained unknown and which he saw as the most interesting aspect of his hobby-turned-vocation.
"In a way, it's about the story. It's the story behind that pretty piece of paper that intrigues people."