When the red-sauce joint Queen, in Brooklyn Heights, closed in 2020, David Barnett left a note on the roll gate with his contact information and an inquiry. Did they have plans for the sign? Situated just a few blocks from the courthouse, the Italian restaurant was rumored to be a meeting place for cops and mob bosses. And its glowing, red neon sign, with a crown illustration in the Q, was a neighborhood landmark.

Eventually, almost three years later, Mr. Barnett, who is the founder of the New York Sign Museum, got a call. It was the owner of the “Queen” sign, letting him know he received his note and was ready to chat.

The two worked out a deal: Mr. Barnett could have the sign, but if Queen were to ever reopen in the future, he’d make them a replica. Then, in 2024, Mr. Barnett and a team of three others took the sign down.

“So many people came by and just started telling stories, like, ‘I’m in my 50s, but I’ve been coming here since I was 6 years old,’ and ‘I can’t believe it’s closing, it’s truly the end of an era,’” said Mr. Barnett, 39.