M.S. Rau Antiques in New Orleans has room after room and gallery after gallery devoted to 18th-century French furniture, candelabra, musical instruments, rare globes, obelisks, stained glass and music boxes.

Royal Street in the French Quarter of New Orleans is shorthand for the antique and fine-art business, the way Bay Street is shorthand for the Toronto stock exchange. Although I’ve been to New Orleans numerous times, I only recently became aware of M.S. Rau Antiques owing to its almost daily advertisements in The New York Times and less frequent ones in The Wall Street Journal. The ads often feature a European, British or American painting, or an opulent eye-catching piece of jewellery or, well, just about anything that’s historical, artful, collectable, rare, pricey – and frequently quirky as well.

Last month, I decided to visit this extraordinary shop.

Rau’s is thought to be the largest retail antique business in North America, but what makes it so remarkable is its variety, not its size. The company’s president, Bill Rau, is the 57-year-old grandson of the founder, Mendel Simon Rau, an immigrant from the Austro-Hungarian Empire who arrived in the United States in 1908 with only US$12. When, by 1912, he had saved US$500 more, he opened his shop.

The company now occupies two conjoined historic buildings. They have room after room and gallery after gallery devoted to, for example, 18th-century French furniture, candelabra, musical instruments, rare globes, obelisks, stained glass, music boxes and the rarest of gemstones. There were two Matisses, one a drawing, and two Monet canvases as well as a letter in Monet’s hand. I was struck by the way that his penmanship, unlike those of most visual artists, seemed completely unrelated to his painting.

 

The firm is essentially battling against the big auction houses – Sotheby’s, Bonhams, Phillips and the rest – to get the best items and then sell them directly to individual collectors. Bill Rau’s young daughter, Rebecca, is being groomed to become the fourth generation in the business.

The Rau family and their staff work in a cosmopolitan profession that can’t be separated from such concerns as currency fluctuations and customs brokerage. Bill Rau has worked with Interpol to battle theft and fraud in the fine-art world and has helped descendants to reunite with works that were confiscated by the Nazis.

Recently, Rau has been placing very expensive full-page colour ads in The Economist, including one offering an Enigma encoding machine used by the Nazis to encrypt messages – until Alan Turing and his colleagues at Bletchley Park in England managed to crack the code and render the contraption useless. About 100,000 of the machines were manufactured in the 1930s and 40s but few survive.

 

“I was in my office when I received an e-mail from a gentleman in Romania whom I didn’t know.” It seems that it wasn’t clear whether the machine could leave the country or what currency the owner would accept (Rau is, of course, fluent in U.S. dollars, sterling, yen, Swiss francs, euros and so on). “Eventually, it arrived in London.” Rau has a full-time staffer there acting as a scout. He has another in Tokyo.

Nothing in the Rau showrooms carries a price tag (for that would be in poor taste). But by burrowing in the company website, one can usually find an asking price. In this case, the figure is US$248,500.

 

In the course of a couple of hours, I saw a camel whip that Napoleon carried in his Egyptian campaign as well as a bronze copy of his death mask. For no particular reason, there is a thick indoor forest of fancy walking sticks (and one very plain one, the former property of Mark Twain). There are Bronze Age axe heads from about 600 BC, but they’re not the oldest bit of inventory. That would be the skeleton of a huge Siberian bear from the Ice Age. With a little curatorial restoration, it stands erect. It’s terrifying.

Another curiosity is what must surely be the world’s largest and most elaborately carved and decorated billiard table, created in what is now Australia in 1880. It was once exhibited at Buckingham Palace. The Prince of Wales, the future Edward VII, was so large that he needed a huge custom-made bathtub. So he naturally coveted a pool table perhaps three times the size of a normal one. But he was never able to secure it for himself. When I visited the shop, it was going for US$750,000.

The most startling display was a large amount of material concerning the assassination of John F. Kennedy and, in particular, the failed attempt by Jim Garrison, the district attorney of New Orleans, to convict a local businessman whom he believed was one of the conspirators.

There is a huge archive of files, letters, photos, interviews, depositions, affidavits and other court documents, including testimony that was thought to have been lost after the trial collapsed in 1969.

 

“Well,” Rau told me, “Jim Garrison, you know, was somewhat paranoid during this period and he asked his executive assistant, who had worked with him for a long time, to hide the stuff in her closet at home. It lay there for years and eventually passed to her daughter, who offered it to me.” The current asking price is US$168,500.

That may sound a little steep, but the collection comes with two first-generation copies of the Zapruder film. “And there are only three of those. The other one is in the National Archives in Washington.”

And that one is certainly never going anywhere else.