Oh hell, I forgot about those.
My uncle still has one buried in his yard somewhere. We were going to dig it up in the '80 to prevent it from caving in, but everyone forgot were the stupid door was.
Its still there, somewhere.
Ours was just a 12x12 cinderblock room right off the family room. Very cool temperature, so as I said, perfect for a wine cellar. Protection from the Russians - not so much.