I kind of remember someone said in an old thread that they used to sell them in Germany and Europe and that it was OK as long as they had the "copy" on them. I just looked for my Buffalo nickel copy that I found to show you but, I must have put it in a safe place.
I have at least a couple of those (got my last one earlier this month). I have found a couple copy buffalo nickels too as well as even smaller versions of a quarter.
Although all of mine have been in the inside reject slot of the coin machine mixed in with all the grime, lint, and "mainly" foreign coins.