I have read that a special 9 minute episode was filmed at the request of the U.S. Treasury in order to help promote U.S. Savings Bonds. Here is a description that I found online:

"The bar gang tries to show Diane how U.S. savings bonds are a good investment. "

Does anyone have this?

Did the United States Government Create a Special Never-Broadcast Episode of Cheers? (http://legendsrevealed.com/entertainment/2016/10/18/did-the-united-states-government-create-a-special-never-broadcast-episode-of-cheers/)