Then, earlier this month, Brigid Brown packed them up, took them back through the chandeliered foyer of the hotel and plunked them down on a table - as part of a Waldorf amnesty program that seeks the return of pilfered property, no questions asked.
"At first, I thought, 'Was my husband's grandfather a thief? How could he do this?'" she asked.
The spoons joined dozens of other items that are back in their rightful place, including teapots, coffee pots, creamers, coasters and dishes for nuts.
Just don't call them stolen items.
Each was "secretly checked out," the hotel says on its Facebook page. And "we're giving you the chance to give it back."
The Waldorf's fancy what-nots are trickling back with stories of human lives, loves and losses going as far back as the early 20th century. They trace the history of the 129-year-old hotel that fills a whole city block on Manhattan's east side. It has hosted every U.S. president - including Barack Obama this week - and been home to celebrities from Frank Sinatra and Cole Porter to Paris Hilton.
But the program that started on July 1 offers glimpses into more ordinary lives of people who came to the Waldorf for something special, such as a wedding night, an anniversary, an award or special vacation.
Some items are of no particular value, except emotional, such as a "Do Not Disturb" sign from a couple's wedding night that an archivist pulls out of a cardboard box along with postcards written by the blissful guests.
The new collection will be displayed in glass cases in the lobby with other objects and photos from a celebrity-studded past.
Beyond historic nostalgia, the project has a new-age business purpose: To raise the profile of an old, iconic institution in today's social-media marketing world.
Matt Zolbe, the Waldorf's director of sales and marketing, hopes images of interesting returned property the hotel is loading on Facebook, Twitter and Pinterest will be retweeted or reposted "to attract a new generation to the Waldorf," where room rates start at about $400 a night.
Christine Hayner, a 25-year-old Waldorf sales manager, says she's never helped herself to anything at the hotel. But her grandmother did, on her wedding night in 1949.
This summer, while at the family beach house on the New Jersey shore, a Waldorf silver fork suddenly appeared in her grandmother's hand.
"She said, 'I have something from your hotel, and I want you to have it - it's important to me,'" Hayner quotes her as saying.
The granddaughter accepted the salad fork, more than a half century after it disappeared from a cart that brought a room-service meal to the newlyweds.
But then, said Hayner, "I thought, 'What am I going to do with this?'"
Three days later, she got the answer at a business meeting where Waldorf executives announced their amnesty idea.
But other objects are still missing, including thousands of demitasse spoons that were the most popular stolen item - easy to tuck away in a pocket or purse.
One unique piece never made it back: the glass door to a shower in the Waldorf Towers apartment of Sinatra and his wife, Nancy, with their initials carved into it. An unnamed seller once offered the Waldorf the door, "but it's not a hotel practice to purchase items that may have been stolen," said Zolbe.
Waldorf archivist Alex Duryee said surprise packages have come from across the country, from California and Texas to Massachusetts and Louisiana.
Two silver butter knives were returned to the front desk by a relative of a New Jersey woman who attended separate luncheons honoring her for selling the most dresses for charity.
"She took a knife each time," Duryee said. "They were her secret trophies."
Brown, who lives in Somerset, N.J., and returned the three spoons earlier this month, said the story of how her husband's grandfather swiped the silverware while working as a clerk at the Waldorf in the 1920s and '30s is now part of family lore. She's kept them in a home drawer, tied together with a rubber band.
But sentimentality dies hard.
She sheepishly admitted there were actually four stolen spoons.
"I wanted one as a keepsake."