Not sure if this has ever been invented and not sure in this forum if I should take it to the secret sessions. This would be a fragile gimmick, but my idea would be to make a SS with two sides so a different coin is actually sandwiched inside. Another take on this would be a m****t coin and two very thin shim pieces that could slide off. Perhaps they are also "attractive" and could stick together as they come off. I'll leave it at that and see if this ever existed, was tried and not practical, or should be discussed elsewhere.

One could use the original Slippery Sam coin set in that way, taking the smaller attractive English Penney, it's Half Dollar L gaff and then the L English Penny (that usually sits on the attractive half dollar coin) on that.
Hope that's of some help,
J

Oh, I see! Thanks!