With a wave of urban redevelopment sweeping the city, Fung says there's never a shortage of oddities to pick up. But it's not as easy as it was.

"In the past, people were free to enter deserted buildings. If letterboxes were overflowing with letters, or water meters read zero, it meant the building was about to be demolished. Drug addicts took the old metal pipes and copper wire for resale. We only picked up things that had fun or commemorative value. I like old photo albums that show different family stories."

Before Lower Ngau Tau Kok Estate was demolished in 2010, Fung spent a month there picking up leftover objects such as watches and coins. As drug addicts moved into the vacated premises, they were padlocked and entry was barred. So Fung and his peers found a way around the obstacle.

"We paid tea money to security guards to let us in. We also talked to the construction companies. They saw that by letting us walk off with the old furniture and whatever, it lessened their workload."

Hong Kong's throwaway culture is an added bonus. Fung says he often gets calls from people wanting rid of old belongings when they refurbish or move homes.

"Old apothecaries and picture-taking shops also find us to help clear away their stuff," he says. "A year ago, an old campus of a left-leaning primary school in Pok Fu Lam was converted into a canteen by the University of Hong Kong.

"Before the conversion, I found boxes of funny documents from the 1950s that recorded why students got demerits or switched to another school, and other more mundane things that happen to students on campus. Recently, a woman bought 100 of the documents for HK$200 each."

Fung says Hongkongers don't realise the special value of the things they throw away.

"Unlike in developed countries, people in developing nations throw everything away, like fans, air conditioners. That's because they think they will lose face by using old stuff," he says. So he visits developing countries such as India and Vietnam to add to his collection.

"Old products reflect their times. Take electroplated glass water cups; the glass shimmers with gold. These cups must have been made in the 1960s and 1970s as the technology was later banned after it was found to be toxic."

Fung says his clients are private collectors, movie industry art directors, interior designers and restaurants or shops that want vintage decor.

He often makes a small fortune on purchases from undiscriminating sellers.

"Three years ago, a Central collector who often sells me things asked whether I wanted to buy some joss stick containers and two drawings. One drawing bore the signature of famous Chinese painter Feng Zikai.

"I thought it was authentic, because there were dozens of words on it. Fake paintings don't have so many words because they can easily be exposed as forgeries. Later, a Chinese University professor authenticated it and I sold it for HK$400,000."

Another enthusiast of vintage curios is Mido Dhillon. Born in Hong Kong and fluent in Cantonese, Dhillon studied fashion design and set up a shop in Tsim Sha Tsui in 1991, selling clothes and antique spectacles.

On his frequent overseas sourcing trips, he visited flea markets in search of decorations for the shop. His collection grew, and in 2005 he decided to open his Sheung Wan shop - Select 18 - to sell the curios.

His collection ranges from Shanghai barbers' chairs to Queen Elizabeth memorabilia, taxi meters from the 1960s and shop posters promoting the exchange of bottle caps for gifts. "Like most Hong Kong people, I miss the days before the handover. So I have a penchant for things related to the colonial administration," he says.

"I come from a family of civil servants. I used to live in government staff quarters, so things like standard-issue furniture and cutlery mean a lot to me."

He says he has a dream to turn his house into a mock police station or government staff quarters from the old days.

Dhillon often hikes in the New Territories, he says, where some of the older shops are still plastered with advertising posters from the 1970s.

"They are like a microcosm of society [at that time]. TV adverts were not so popular then so the shops were a platform for soft drinks and snacks companies to place adverts.

"A collection of the advertising displays from those shops can help you understand the zeitgeist of the time."

Dhillon visits a different district each week to hunt for new pieces. "I like window shopping. I always discover new things on visits to the same district. I've bought old taxi meters from a vehicle repair workshop. I have so much stuff now that I need two warehouses to store it all."

Andrew McRae divides his collection locally between three Museum Context shops - the first opened in 2011 in the Landmark Atrium, followed by Prince's Building and PMQ in Central. The former architect, who also has two shops in Edinburgh, says all the products on sale in Hong Kong are from his private curated collections.

"Everything I bring into the collection is very personal. The antique and vintage pieces are one of a kind I select from trading partners," he says.

"We focus on British-style heritage with some European elements. We get lots of sporting memorabilia, like old tennis racquets, golf clubs and croquet mallets, which are quintessentially English, and original pigeon racing clocks. Pigeon racing was very popular in England in the 1930s."

McRae has many items from the 1950s and 1960s golden age of travel, such as plane parts and maps. Second world war memorabilia features strongly. On display at the Landmark shop are original Tommy (English infantry) helmets and shell casings from battlefields.

"They were brought back by the servicemen as mementos. Each one is stamped with a production date," he says.

McRae says he likes collecting old things because each one has a story to tell.

"There's a heart-shaped ashtray [inscribed with the image of a couple] made from parts of wreckage from a German bomber. The bomber's parts were melted down by someone who was in the battlefield and turned into a piece of art."

A keen stamp collector since childhood, McRae says his passion for collecting vintage items developed while working as an architect in Britain.

"When I worked on different commercial and residential projects, I had to think of how we could bring the space to life. I developed an interest in restoration and heritage conservation through my work in rejuvenating old buildings. I'm intrigued by vintage elements in both architecture and general objects with a history.

"From my work, I also know people from the architecture salvage business [whom I do business with]," he adds.

McRae says he called his shop Museum Context because he wants visitors to enjoy a cultural experience.

"Lots of young people just want modern things around them. They should know about the educational value of collecting things in an era when so many people are consumed by technology," he says.

McRae says he has lots of well-heeled customers who don't mind splashing out to surround themselves with reminders of a bygone age.

"I have a Chinese customer who is passionate about aviation. We get materials salvaged from decommissioned Royal Air Force planes through contacts in the UK. We get the actual components of the planes, like bomber control units. I am trying to source an ejector seat for him.

"He wants to create the entire front section of a second world war plane in his house."