A peek inside Grand Central Terminal in 1939

From the New York Central Railroad comes this cool cutaway poster into Grand Central Terminal circa 1939, when train travel reigned supreme.

The zodiac ceiling in the main concourse looks beautifully blue. There’s the main waiting room, now called Vanderbilt Hall, as well as a restaurant concourse, plus various lower levels connecting passengers to commuter trains and subways.

What happened to the art gallery on the third floor above the main waiting room?