Awhile ago I had picked up some Milk Caps and rigged one up like a split coin so that I could do a Three Fly style routine. Here’s the routine with some patter:
These milk caps are as unusual of an object as something like a silver dollar to anyone under 30 years old. People get hung up on what’s an ordinary object, and a large size silver dollar isn’t an ordinary object. The USA stopped using the large size dollar coins in the late 1970’s or over 40 years ago! The audience has to make a leap in time for either prop. I’d argue that the milk cap is easier to justify because it’s something they haven’t seen before. Where a large size dollar coin is similar to something that exists, but not the same. You can justify the milk caps through presentation, however most magicians don’t justify why they have old coins.