You say, “In 1957, a NASA rocket was displayed inside the terminal…” but NASA didn’t exist until 1958.

That rocket actually belonged to the Army. It was so tall that a small hole had to be cut in the ceiling for its nosecone.

There is no “opal clock” at Grand Central, although many web sources join you in spreading this canard.

The four-faced, spherical clock atop the information booth uses OPAL GLASS, a common, non-precious translucent material often used in lamps. It’s also known as “milk glass” and, I can assure you, is no more made of opals than it is made out of milk!

Even if the NY Central or the Vanderbilts _had_ wanted to do something as crazily expensive as use a semi-precious stone for the clock faces, the fact is that no opal large enough for even one face was discovered until relatively recently. And it’s not translucent!

A New York Times article from the 50s, when the clock was being cleaned and restored, confirms what I’ve said here, noting: “Each of the glass faces was twenty-four inches in diameter…”. That article can be accessed here: http://select.nytimes.com/gst/abstract.html?res=9A05E5D8173AE53BBC4851DFB766838F649EDE