David Thorp became McLeod's boss man after his father's death in 2005, before that he'd been managing the business for a few years.
He pays tribute to his father's abilities as an astute businessman.
"That is the reason why McLeod's is still in business today."
Now at what's generally recognised as retirement age himself, how much longer can he and his long-serving staff keep the flagship business afloat as they square off against big box retailers, chain stores and online retailers with their cost-cutting abilities and mass market appeal?
That is the burning question David is unable to answer, other than "why give up now?".
Miraculously against such stiff national and international competition McLeod's has continued to survive and thrive.
Which of McLeod's perceived competitors can offer that traditional book shop feel it does?
It smells like a bookshop should, browsers are welcome, no one hassles those who curl up in a thoughtfully provided armchair for a read. Fixtures, fittings, the gold lettering denoting categories and its antique clock have passed from site to site. Authors' events are held regularly, books are launched there and McLeod's book club's thrived for years.
Staying in the book business hasn't been an easy ride.
If Thorp the younger had a tattoo emblazoned across his forehead it would read "localisation", he'd likely have it repeated across his hands and torso. It's certainly engraved on his heart.
He's adamant keeping things local is the reason McLeod's is celebrating such an impressive milestone. He has no time, none at all, for "rapacious developers and landlords". He dates the CBD's decline back to the 80s when out-of-town investors swooped in buying blocks of shops and putting the squeeze on local owner-operators by sending rents skyrocketing.
McLeod's nearly didn't make it to its 50th birthday.
In 1982 the Thorps opened The Daily Post, as it then was, to be greeted by a for sale ad – the property was 146 Tutanekai St, McLeod's rented home since its earliest days.
An Auckland developer had bought the block without a word to existing tenants.
The Thorps clung on for five years but when their rent shot up from $7 a square metre to $32 reality hit home.
"We were in an impossible situation, could no longer afford to stay," is David's realistic analysis of the situation the family business found itself mired in.
Local man, the late Doug Fenwick, was in the process of building the city's parking building with shops planned for its Hinemoa St frontage.
Telecom had shown firm interest but when the corporate biggie failed to meet the appointed lease sign-off date, David was given 12 hours to decide if he'd pick up what Telecom had walked away from.
"I was young, not all that experienced, my parents were overseas so the snap decision was mine, I said 'okay, we'll take it'."
The move from the former premises was a massive wrench, but the shop remained as popular as ever.
However when Fenwick sold the building the new landlord immediately upped the rent by 50 per cent, again the financial squeeze was on.
"That meant $40,000 of our profit would be siphoned out of the business ... that's the situation that's forced so many small businesses out of the CBD."
The Thorps vowed to remain – casting about for their third shop, it was back in Tutanekai St "where the Majestic Theatre used to be".
The intention was that this one was for keeps, but when the building's owner and close family friend, Jim Larkin, died an overseas investor stepped in, the inevitable happened, the rent spiralled.
Move four was to the Pukuatua St premises McLeod's have occupied since 2012.
David wasn't born to be a bookseller. The self-styled hippie-surfer's initial ambition was to teach. He was working towards an Auckland University BA, supporting himself with leather work, when reactive arthritis set in.
His introduction to Rotorua was being treated for it at Queen Elizabeth Hospital.
"They said if it didn't recur before I was 30 I'd be okay, it didn't and I was."
Way behind in his studies and losing his bursary because of so much missed time, he joined the ranks of the adventure travellers.
"There's always been a touch of the gypsy in me."
By the time he'd satisfied his first bout of wanderlust (his traveller's tales run into several editions) he tried his hand at carpentry, that included rebuilding work around Darwin in the wake of Cyclone Tracy.
Home, he settled at Pukehina "a blissful haven to lick my wounds after a broken relationship with the girl I'd been travelling with".
He hadn't been long back and was framing pictures when his father fell off a ladder, breaking his wrist.
"I hadn't any interest whatever in getting into the business, I was an outdoors person, enjoyed working with my hands. I told Dad I'd help out but I still had travel to do.
"He understood that but when he took me out the back and showed me the first step of bookselling, opening a box of newly published books, I was hooked. It was like that feeling you get when you unwrap a present, I've been getting that feeling pretty well every day for 40 years, it can't be replicated."
Following further "adventure travel" he met his wife-to-be, Lynne. She too was steeped in the business of books, working as a rep for major publishing house AH & AW Reed.
"I thought she was a bit of all right, lured her out of Auckland with a Kombi van trip around the South Island, we married 32 years ago."
DAVID THORP
Born: Otorohanga, 1953.
Education: Otorohanga South Primary. Mt Albert Grammar (boarder), Auckland University (degree not completed).
Family: Wife Lynne, two sons, daughter. "Our first grandchild's due around Christmas."
Interests: Family, books, travel, music, playing guitar. "I still surf at Raglan." Walking, tramping.
Favourite book: A Fine Balance by Rohinton Mistry.
On the book trade today: "It's virtually non-existent, McLeod's holds on because we give a truly unique book shop experience that the big boys can't begin to do."
Personal philosophy: "Live simply, be nice."