Here is a nice blog with a lot of pictures :
http://www.funkygoods.com/schwarzschild/2013_05/2013_05_24_2.html
This lathe enabled the recording of Emperor Hirohito's voice at the end of WW2.
More details here : http://en.wikipedia.org/wiki/Gyokuon-h%C5%8Ds%C5%8D
According to this blog, the record is kept in a special case at a constant temperature of 4 degrees Celsius into nitrogen, the glass preventing UV rays and infrared light from passing.
By the way here is a short excerpt of Japan's longest day that try to recreate this moment :
Lucien