Among the handful of knickknacks that decorate my less-than-tidy workspace, piled on a bookshelf between impressive-looking designer monographs I've never actually read, sits a random assortment of crystal ornaments that I absolutely adore. Tacky they may be, but each piece holds sentimental value. My favorite is a fat paperweight in the shape of a pencil, which was a Christmas gift from designer Oleg Cassini sometime in the late '90s or early aughts.

It's worthless, I'm sure. But to a writer who specializes in fashion, it means everything. A lot of memories are reflected in its facets, foremost the semiannual lunch dates Cassini and I enjoyed at an unassuming Italian restaurant on the Upper East Side, near the Elias Asiel Mansion that was his residence for years. Cassini was a trip, one last relic of a bygone time. Compact and fit, sporting a debonair mustache, dark-lensed glasses, a low-cut '50s-style jacket, and cowboy boots, Cassini, the son of an impoverished Russian-Italian count, was the embodiment of an Old Hollywood-era dress designer.

Normally we would discuss changes in his business — he had been the longest-working designer in America when he died in 2006, at the age of 92. He liked to talk about politics and the ladies he dressed, but inevitably the conversation would turn to the bugbear that haunted him for years: accusations that the designs he crafted for his most famous client, Jacqueline Kennedy, were actually ordered as line-for-line copies of French couture. Hubert de Givenchy certainly thought so, and Karl Lagerfeld claimed that Chanel had the receipts. Cassini denied this strenuously, and his well-documented correspondence with Kennedy showed the depths of an extraordinary collaboration between a designer and a first lady.

A year before Cassini died, I accompanied him to the now-shuttered Lord & Taylor store on Fifth Avenue, where he received an award in front of a crowd of more than 7,000 people. I'll never forget how, while I tried to interview him, he kept pestering the young models wearing his designs to go out with him. "For the first time I realize that I am no longer just a designer," the notorious jet-set playboy said. "I'm a guru."

In fact, Cassini was a great innovator, the first designer to recognize that the potency of ornamental fashion, such as that worn by royalty for centuries to illustrate their wealth and position, could also be applied to American politics.

Today it is well understood that world leaders and their spouses use their appearances as tools of communication, none so literally as Melania "I really don't care, do u?" Trump.

Cassini had started his career in Hollywood, where he met and married actress Gene Tierney and later pursued Grace Kelly, Anita Ekberg, and Marilyn Monroe. When he was tapped as Kennedy's dressmaker in 1960, he approached the role much as would a costume designer creating a wardrobe for a character, sketching dresses with strong lines inspired by Egyptian hieroglyphics and antiquities, along with a pillbox hat based on the bust of Queen Nefertiti. Coats were designed in the manner of a Cossack uniform, with large buttons that became a Kennedy signature.

In the age of television the bold shapes and colors made the first lady stand out onscreen. Cassini designed a red wool suit to complement the uniforms of the Royal Canadian Mounted Police for a visit to Canada, and he chose a shocking pink raja coat when Kennedy was to meet Prime Minister Jawaharlal Nehru, eliciting awestruck reactions in India, where she was compared to Durga, the goddess of power.

"She was the perfect model for very simple lines — a minimalist par excellence," Cassini wrote in his book A Thousand Days of Magic.

What really got me thinking about Cassini recently, however, was not the pencil. In May, Doyle began advertising an estate sale of Cassini's property from his two Manhattan homes and his Oyster Bay mansion on Long Island, though not with the blessing of his widow, Marianne Nestor Cassini, to whom Cassini had been secretly married. Marianne and her sister Peggy, who ran Cassini's operations, have clashed with the children and grandchildren of Cassini from his marriage to Tierney. Marianne even spent six months in a Nassau County jail for refusing to turn over financial statements in one of the ongoing cases, making it impossible for the heirs to accurately assess the value of his estate.

And so, amid this sorry state of affairs, I find myself absorbed in a detailed examination of the detritus of his life, as revealed in the Doyle auction catalogue and its 750 lots. There are long notes from Kennedy, including a nine-page letter valued at more than $10,000; sketches, of course; and photographs of the designer with President John F. Kennedy. There are French paintings of battle scenes, leather chesterfield sofas, toy soldiers, plates shaped like lettuce leaves, an umbrella stand that looks like a boot, silver tea sets, and piles of Native American jewelry that Cassini loved to collect. There are more-personal things as well, including his boots — 25 pairs of them in three lots that are each expected to fetch just a few hundred dollars.

It's a sad ending to an important legacy, but there is one highlight of the sale: It turns out that Cassini kept vast stores of glass objects from his collections, including candlesticks and plenty of whimsical paperweights, presumably to give as gifts to anyone he thought he might inspire.

For more stories like this, pick up the August issue of InStyle, available on newsstands, on Amazon, and for digital download July 19.