It's a lame prop with what might have been a good idea would it be manufactured properly.
Other than them looking at it from a meter away you cannot let them handle it or they will
understand the gimmick.
Magnets are not aligned AND there's nothing that you can do about
it NO WAY to fix it!
If you really want to do this, Go get a "medal" at a toy store or gift
shop have it engraved at your local printer with your favourite card. In fact it should be quite
affordable to do it this way so make a few.