Persuading the "rusty relics" to reveal their age was about as difficult as getting a whitebaiter to confess the size of their catch.
But, with a bit of flattery, the truth - or as close to it as possible - was soon out.
"I can't believe how good looking they all are.
"They must have improved over the years," Wanaka's Jo Wallis - wife of transport operator George Wallis - said as the men posed for media photographs on a former Ministry of Works D8 Caterpillar dozer now owned by Joe Gilman, of Stillwater.
And so the stories began to flow.
Sonny Yates (73), of Kaiapoi, was based at a camp near the Gates of Haast bridge and is credited with being the first to drive a Land Rover through the Haast Pass and the Haast River down to Roaring Billy's Camp in 1957.
The late-Saturday-afternoon trip was memorable, because when he arrived he asked all the Ministry of Works men to sign a bottle of beer, which he promptly drank, then threw away the valuable empty.
"I don't know why I did that. Oh dear," Mr Yates said.
Slips often blocked the road to Wanaka so Mr Yates and friends would radio colleagues at Alexandra to ring up the Wanaka taxi driver, Bill Anderson, to come and pick them up.
The men would walk over the slip to the taxi and go into Wanaka for a beer, and Mr Anderson would return them later.
"I reckon there must have been quite a few shoes left in that slip, all the times we were going backwards and forwards," Mr Yates said.
Road building was an adventure for dozens of young men, who typically worked stints of about three or more years, based at isolated camps between Makarora and Haast.
Andy Benington (79), of Alexandra, was a repair man for Tractor Workshops, based in Dunedin, and first went into the Haast Pass at the end of 1956.
"It was late at night, 10pm, coming round The Hinge.
All I could see was rock face on one side and solid black the other way ... [The next day I was] looking out the window at a 500- to 600-foot (152m-183m) drop. The next step was a big one," he recalled.
Brian McCarthy (85) was among 14 men who came down to Haast from Hokitika in the '50s.
His story sparked a just-published book on the making of the road by Waikanae author Dave Grantham and Mr McCarthy was on hand to help launch it in Haast on Friday night last week.
"I was here in 1949. I was here for 18 months that time and then I came back from '52 to '55 to do the rock bluffs ...
"Oh, there wasn't much rain. We had a big flood in 1949.
"There was 21 inches (533mm) of water through the old Cron homestead that had been there for 76 years.
"Two of us rowed a boat up in six-foot (1.83m) of water between here and the beach.
"The [Haast] river just rose and rose. The rain gauge at Haast held 12 inches (304mm) of rain and then overflowed.
"We spent the next nine months building a stop bank for the aerodrome.
"But the rain wasn't that bad.
"When we were doing the rock bluffs, the public works department knocked off at 2pm on a week day and we still got a day's pay.
"We would watch the waterfalls. If they got out so far, we knew we had half an hour to get away home," Mr McCarthy recalled.
Many of the men said they came to work in South Westland to get away from the rest of the world and hunt deer.
They worked nine-hour days, six days a week, with Sundays off to go hunting.
They all loved "boat day", which occurred once every three months, when they would go fishing at Jackson Bay.
Martin Gugich (70), of Hokitika: "It was brilliant for us as young guys. It was the type of work we wanted to do.
"We would get amazingly wet. There were no cabs [on the dozers]," he said.
The four Stewart brothers of Hokitika, Pat (75), Frank (73), George (69) and Dave (64) all had turns working on the road during the 1950s, covering the entire decade between them.
All but Frank were at the reunion.
Pat Stewart recalled "rain, rain and rain. Oh, but it was good.
"In those days, you liked your work. I don't know why. But you went to work," he said.
Those who didn't work soon got short shrift.
Mr Gugich recalled a 16-year-old boy who wouldn't get out of bed, so he took the wrapper off a stick of gelignite, put a candle in the wrapper and lit the wick.
"I threw it under his bed. Well, he came out of his bed and just about knocked me over on his way out the door.
"He was completely naked. We didn't have a problem with him after that," Mr Gugich recalled.
No mercy was spared those whose sartorial elegance let them down.
Dave Stewart recalled another worker who wrote to his mother asking for warm clothing and was sent a pink long-john suit, which he wore to work with nothing on the top.
"That was no good for courting. But then, there was nothing to catch," he said.
