Over the last quarter-century, the decorative arts that bewitched earlier generations have somewhat fallen out of fashion. Back in the ’90s, the Upper East Side was all “period rooms in the sky,” recalled Patrick Sheehan, a top appraiser at Gurr Johns. Today, though, everything from Sèvres porcelain and Puiforcat silver to Louis XVI commodes is down from their highs. Sotheby’s and Christie’s have downsized their European decorative arts teams and consolidated their auction calendars. But even though there are comparatively fewer Regency tables coming to market these days, there are estates and collections that need to be sold—and the demand on the buyer side is higher than you might think.