Artsy Zip Guns. According to the blog I found these on, artist Tom Sachs realized that zip guns could be made cheaply and easily, then sold to New York gun “buybacks” for $300 each. Being an artist, of course, he couldn’t resist giving them some flair. You can find more photos here.
For those of you wondering, it IS legal to build a firearm at home, as long as they follow the NFA rules (no Short Barrel Rifles, machine guns, etc.) and they are not for sale or profit. So IF Mr. Sachs actually sold them, he was breaking that second rule, although most “buybacks” stress the “no questions asked” rule.