I had never been to Musso’s myself. So on a recent warm afternoon, I met Mark Echeverria, Musso’s chief operating officer, in the original dining room there for lunch.

I was, of course, interested in the celebrity lore and curious about what it was like to have one of the world’s most famous filmmakers take over your business for almost a week. (Mr. Tarantino, according to Mr. Echeverria, treated Musso’s like a palace and the staff members like kings while they were shut down for filming.)

But what fascinated me more was how — in a world where restaurants run on notoriously razor-thin profit margins — Musso’s had managed to stay open for 100 years, without consultant-prescribed rebrands, or menu overhauls.

[Read Tejal Rao’s ode to old-school L.A. restaurants like Musso’s.]

Mr. Echeverria, for whom Musso’s is a family business, attributed that success to the restaurant’s commitment to keeping everything the same.

When the recession hit, he said, the restaurant got by because of its loyal customers.

“We actually saw the opposite of what the nation saw,” he said. “Our sales increased.”