Among the guests were a couple of Customs veterans who made the service their careers.
Like Cyril Wilson, who joined Customs in Wellington in 1958, moved to Hawke's Bay in 1983 and rose to the position of operations manager in Napier - putting in more than 45 years.
"I had been looking for a job and heard about Customs so thought I'd give it a try," he said.
He made an appointment for an interview and at the end of it the officer simply said "okay, you've got the job ... would you like a beer?"
With a smile Mr Wilson said "I thought this is the job for me".
His first job was being put in charge of what was called "the coffin".
A long box in which import licence applications were filed.
"That was my first job and after a month I was asked if I wanted to work overtime and I said yes - the overtime was posting out licences."
But he stuck it out and moved on to more demanding roles, like boarding ships at sea to carry out searches for contraband.
Dennis Flowers also put in many decades of service, starting out in Wanganui where the Customs in those days did not have a vehicle.
"So we'd push-bike around."
He would visit petrol companies to "dip the tanks" and breweries to carry out excise duties.
Mr Flowers also served in Wellington before spending the last 10 years of his service in Napier.
"Very happy years," he said.
They chatted with the current generation of Customs officers working the Napier beat, including Joanna Gibb who has been in the service for four years, starting in Auckland before moving here with her Bay-born husband two years ago.
Customs Minister Nicky Wagner paid tribute to the service at a function in Wellington earlier in the week.
"From the old days of opium, war, risqu books, importer scams and transistor radio smugglers, to today's methamphetamine, counter-terrorism, objectionable material, fraud and money laundering - the targets have changed - but Customs' focus and commitment remains the same," she said.
-Last year, Customs processed a record 11.2 million arriving and departing travellers, processed 7.8 million import transactions, and collected $11.847 billion in Crown revenue.