One institution that has made an effort is the National Australia Bank. This is fortuitous. The bank, celebrating its 150th anniversary this year, has kept enough corporate history to be able to stage a travelling exhibition, which is completing its national tour in Melbourne at the moment (see details below). October 4 is the official birthday, to be marked with a series of celebrations on the Yarra.

To be specific, the bank had kept a lot of its history but it required the appointment of a full-time heritage collection manager in 1993 (see My Collection) and the services of a professional curator for a decade to catalogue the contents. A database of more than 3300 objects has been compiled, with photographs, and the undertaking is far from complete. This is a monumental job but smart corporations are now starting to see the value of this process.

That's value in terms of corporate identity although an archive as extensive as NAB's would also be worth a great deal in monetary terms, not that it's ever likely to be sold. Banks naturally keep old currency and this on its own is worth a small fortune these days.

For example, a specimen sample of a National Bank of Australasia ?1 note issued in Western Australia before 1910 is featured on the NAB150 heritage website. Rare currency expert John Pettit values this single item in excess of $100,000, the exact value depending on condition. NAB has a full set of this series, in mint condition, plus untold others of historical significance. The total value of the NAB collection is not revealed but is high enough for it to be kept in a separate high-security complex on the outskirts of Melbourne.

In NAB's case, the process of creating an archive is complicated because of the acquisitive nature of financial institutions. What was then known as the National Bank of Australasia first opened for business at 8am on October 4, 1858 in Melbourne with capital of ?90,000. Since then it has acquired or merged with eight other banks including long-forgotten outfits such as the Colonial Bank of Australasia (in 1918) and the original Bank of Queensland (in 1922).

The Bank of Queensland was the result of a merger of the Royal Bank of Queensland with the Bank of North Queensland, which explains why a smart briefcase belonging to D. MacDiarmid of Townsville was found in the NAB archive. It belonged to a manager of the North Queensland operation and is dated circa 1880. This relatively small bank is now part of the history of today's large corporation. A more recent merger with the Commercial Banking Company of Sydney (1981) is also significant. The CBC was even older than the National - it was established in 1834.

Others to merge with NAB include the Ballarat Banking Company, picked up in 1955, and the Bank of New Zealand (1992). NAB also took over MLC in 2000.

The heritage collection ranges from the important (such as the National Bank of Australasia's July 1858 Deed of Settlement, the original constitution) to the ephemeral (a 1966 Meet The New Currency Lads decimal booklet). The former is priceless, the latter could be picked up for $20 or so. Both are important in terms of our banking history.

Other important documents on display include the 1910 Rules and Instructions for Officers of the Commercial Banking Company of Sydney Limited, a code of conduct for those employed by the bank. This can be contrasted with the NAB's dress code for bank tellers from the '70s.

Also of social significance is the full set of china, monogrammed with the old NAB logo, as used in the executive dining room of the Melbourne head office executive dining room. It's dated 1954 and was made especially for the bank by Spode.

The manager of the NAB heritage collection, Rod McLennan, says this and just about everything on display has come from the archive. Little has had to be gathered from outside. This shows that, unlike many corporations, the bank has long had a culture of keeping its own history. Sorting through and identifying the most important items are the real challenge. "There's still a whole lot to be done," he says.

The NAB150 Melbourne Heritage Exhibition is on until October 10 at the National Australia Bank Building, reception area, level 1, 800 Bourke Street, Docklands. Admission is free. There will be many other local NAB celebrations across the country in early October.

A morning tea for retired NAB bank officers is being held at Federation Square, Melbourne, on October 3. About 900 former employees are being invited.

The 150.nab.com.au website is also well worth a visit. Click on the History link for Photo Collection, Collection Highlights and an Interactive Timeline.

$20

There are many serious collectors of banking memorabilia in Australia. Ephemera, such as this 1966 Meet The New Currency Lads booklet, are readily available.

$100

Much more difficult to find would be this rare Spode cup and saucer with the old NAB logo and made for the executive dining room.

$500

This leather satchel, circa 1880, is a reminder that there was once a thriving Bank of North Queensland. It was incorporated into the Bank of Queensland, itself taken over by the NAB in 1922.

My collection

Rod McLennan, a spritely 77, retired from the National Australia Bank in 1991 after 45 years of service, initially in rural and regional branches, followed by 35 years in personnel.

It was a brief retirement. Because of his interest in banking history he was headhunted for the position of manager of the NAB's heritage collection. He has occupied this position since 1993. His task is to archive the bank's huge collection of memorabilia, a small part of which is being displayed during this year's NAB150 celebrations.

He says he has listed more than 3000 items on the database and there's a lot more to come. One of his personal interests is the gold rush period and associated paraphernalia, such as a set of scales used to weigh the nuggets.

The strangest discovery?

"There's a pair of silver candlesticks," he says. "They were left in safe custody by some New Zealand sea captain, who then disappeared."