In chapter 33 Elinor and Marriane visit Gray’s. Here is information on toothpick cases and some illustrations.

Firstly, Gray’s was a goldsmith and jeweler located at 41 Sackville Street, Thomas Gray, prop. I found a reference here that he was the Prince Regent’s jeweler of choice until 1800 when Gray retired. The link will tell you a bit more about Gray.

Robert Ferrars was buying an adorned, but essentially pointless-and possibly distasteful, given its use- object of vertu- a toothpick case. The examples below are from circa 1790; neither of them possibly fine enough for Robert Ferrars but they will give you an idea.

“At last the affair was decided. The ivory, the gold, and the pearls, all received their appointment, and the gentleman having named the last day on which his existence could be continued without the possession of the toothpick-case, drew on his gloves with leisurely care, and bestowing another glance on the Miss Dashwoods, but such a one as seemed rather to demand than express admiration, walked off with an happy air of real conceit and affected indifference.”