Magician's Coin

Has anyone found a Magician's coin? I had never heard of them until I found the first some 4 months ago. At first I thought it was a rotated die coin, but after consulting with Bill O'Rourke of Coin World (also on this site) he told me what it more than likely was. For those of you who never heard of these, they are coins sold in novelty shops after being altered outside of the mint. There is an outside shell made from one coin that is hollowed out, then there is a second part, made from another coin (usually foreign) that is cut to fit inside the hollowed out portion. This part has TWO sides; one being the reverse of a Kennedy. I've got two different coin faces on the other side. Two are a British half penny, and the other two are a Mexican coin. They usually get stuck together with the alignment out of whack. This is when they get put into circulation. The ones I've found (4) took quite a bit of banging on a hard surface before they would come apart.
I don't think they are worth much, if anything. Just kind of fun to come across and something else to keep an eye out for. I don't think they are made from anything but halves, but I could be wrong.