CVG was the original identifier for the local weather station if built before an Air Field or NAV AID.

Possibly circa after 1947 it was the Radio Identifier of the Air Field or NAV AID, (with a Morse Code ID of Dah-Dit-Dah-Dit/Dit-Dit-Dit-Dah/Dah-Dah-Dit

I can't remember the last time I transcribed written Code

You guys need to open up the books more often instead of relying on Glass... :P