An equally young chap by the name of Morris Elliott wandered into the barber shop and asked for a short back and sides.
Mr Rae pointed him in young Brian's direction and told his young assistant: "It's all yours ... you're on your own".
It was a barber-customer relationship that has run through the decades.
"Yes I'm still cutting Morris' hair ... he hasn't woken up yet," Mr McFlynn said with a laugh.
Mr Elliott said he would not go anywhere else for a trim now.
On the wall of the barber shop Mr McFlynn has a photographic line-up of the long-time customers who come under the "40 Years" and "50 Years" titles.
He said once he embarked on his four-year, 10,000-hour apprenticeship he never wanted to do anything else, but laughed at what it was that first nudged him in the direction of the comb and scissors.
"I wanted to get the hell out of school," he recalls.
The barbershop scene had, like everyone else, changed a lot through the years.
"There were 17 barbershops back then when I started. There's not many now."
One thing that had not changed, and its the one thing he relishes when opening for another morning stint, is the social side.
The natters and chats.
The conversations and the laughter.
"It's amazing ... we talk about everything and anything," he said.
However, there's one subject that is not welcome, and he has made that clear on one of the many colourful pieces of signage which adorn the walls.
At the foot of the prices chart there is a bold footnote which reads "Talk politics ... $50 surcharge".
Humour plays a big part.
Mr McFlynn enjoys a good laugh and when he noted that he actually had a customer at the time he was called for a chat, he said: "Oh it might cost him a bit more this time ... the meter's running".
He has no thoughts of retirement, whatsoever, despite having put in a working life thus far equal to the retirement age.
"I tried to retire once but it didn't work out," Mr McFlynn said.
"Still plenty of work to do."
And still plenty of scissors to wear out.
"Oh I've gone through a few of them all right."
He said while the old fingers were good as gold, he had a few issues with his knees and back, but a bit of medication now and then does the trick.
As for today, it will simply be another day in the shop.
"No, I won't be celebrating the occasion. I can get by without celebrations, but maybe in another five years I might."