A friend of mine actually walked through Moron Grove, IL (with its handgun ban) with a Calico in a holster, while wearing a futuristic costume for a convention. Cops drove right by and assumed it was a prop.
sharpsrifle is correct it is a Williams lel-1 submachine gun
The gun you are talking about is a David marshall "carbine" Williams LEL-1 .22 belt fed submachine gun 2700rpm there is a great artical in the Small Arms Review July 2005 Vol.8 No.10 About the guns that he made. He had around 40 patents on guns like the model 7 and others
Sorry I was hoping to find some pictures on the net but I came up with nothing here are some links http://en.wikipedia.org/wiki/CarbineWilliams
-Josh
I think it was in the Gun Digest of Assault Weapons. I had a copy a few years ago and tossed it. Looked like a fire extinguisher body with two vertical grips.
I recall reading an artical in the Machinegun News many years about the guns of Carbine Williams one of his inventions was a belt fed 22lr that looked very futuristic, I bet it was one of his guns.