This is one I'm working on now. It's a Bicentenial in the limited 40% silver proof. I don't use a scroll saw though. This is being cut by hand with a jewelers saw.
It's also true that it is not in any way illegal. It's a really common missconseption though. Title 18 of the US code swtates that altering with the intent to defraud is illegal. Fraud being the key word. In fact, the treasury gets asked so many times that they made a special statement on their web page that says roughly, Colorizing, cutting, etc, for art or jewelry while not encouraged, there shall be no sanction.
That's why those penny crushers are legal.
Ray