I found this cool replica layout of the 1964 World's Fair at the New York Transit Museum Gallery Annex at Grand Central Terminal. The museum displays historical artifacts of the New York City Subway, bus, commuter rail, and bridge and tunnel systems under the administration of the Metropolitan Transportation Authority. They had quite a few cool items from the 1939 and 1964 World's Fairs. My parents actually attended the 1964 fair, which is now the ground where the US Open Tennis Championships are played. It was really cool to see the exhibits, and that they were free of charge as well. The store has some neat items which would make good souvenirs for yourself or family and friends. You can check our their current exhibits HERE.
Here is a bit more information:
The New York Transit Museum operates a gallery annex in Grand Central Terminal that presents changing exhibitions. The gallery annex is located just off the Main Concourse in the Shuttle Passage, next to the Station Master's office. Please go to What's New on this web site for information on the gallery annex's current exhibition.