Tumblebug named the purpose of the gun. I believe it came with a cartoon instruction sheet, a few rounds of ammo in the grip, and a wooden dowel to clear the spent case. If I remember the article correctly the war came to an end before most were able to distribute them, and the rest were dumped overboard as the ships returned to the U.S.
I remember back in the 70's when I first saw a picture of one of these. I was working in a Chevy garage, and I thought they looked just like the lock mechanism out of a car trunk. The next paragraph in the article explained how GM made them in their stamping machines. So much for the similarity. I'm surprised GM didn't offer to take the extras back to turn into locks.
I don't have the old American Rifleman mag. around anymore, but didn't they talk in the article about how few of these there are left? Or, it could have been stated on the show. Sometime last year they showed it on American Rifleman, and someone actually got to shoot it. That would tell me that the NRA Museum has more than one if they actually let someone use one.