"There are no Patersons," Bruce told me when I asked about the name. "We don't really know anything about Paterson. He must have been in partnership with the grandfather in 1903 but by the 1920s he'd disappeared. An old aunt told us he died fairly early and he was a bachelor, so..."
His name survives though: "I thought of dumping it about 20 years ago when we had a name change," Bruce said (John let Bruce do all the talking, though he did insist that he was listening when I said so). "It was Millar Paterson and Co Ltd and we dumped the 'and Co' and put the 'Metals' on it to be a bit more specific."
The retention of the Paterson was driven not so much by sentiment as by respect for convention, I fancy. The Millars - Bruce turned 70 last Friday and John is 66 - and their working foundry are reminders of a traditional Auckland that urban redevelopment is comprehensively erasing.
Bruce takes me on a tour of the place, first showing me through the "Heritage" folder on the office computer: the bronze threshold of Auckland Museum, some of the ornamentation on the Cenotaph and the magnificent frontage of the General Building in Shortland St are the firm's work. A 500mm-diameter bell for a church on Penrhyn in the northern Cook Islands is packed for shipping. Along with doorknobs and knockers and plaques for business frontages, there are pieces of more public signage: he shows me patterns for the plaque marking the reopening of Grafton Bridge in October 2009 and for one of those bronze plaques that's on every bridge in the country, showing the year it was built and the loading it can bear.
I started to take renewed notice of the place when Hayes Metals moved out of their Newmarket premises just behind the Rialto Cinemas and the building was refitted as expensive boutiques. Dodging Hayes' forklifts had been sport for evening moviegoers for years, and I couldn't help feeling slightly sad that a piece of the old borough's industrial past had gone. I wondered how long before Millar, Paterson went in favour of a place selling $600 shoes.
"I'm sure that will happen," says Bruce. "Let's face it, the biggest developers have no feeling for Auckland City. They've become rich but they've got no empathy with the place. They want a quick buck.
"But whoever takes this business over, if they want to keep it working, they're not going to do it here. If somebody comes and offers us a certain amount of money we'll be gone by lunchtime as the saying goes. But if someone wants to operate it as a foundry they would uplift it and take it somewhere else."
It makes me wonder why the brothers haven't done so long since, not least because they are sitting on a pricey piece of inner-city real estate.
John invites me to look out the window, where the plane trees around Victoria Park are well into their autumn shed and the green fields stretch away to the bridge approaches. "Why would you want to work in a grubby old factory in Henderson," he asks. "You've got all the people walking past."
The business gets a lot of customers who come in with little jobs and pay with eftpos, Bruce explains. It pays the wages. And "you're performing a certain sort of service, aren't you?"