Shredding a signed card in a paper shredder and then putting the pieces together and ultimately restoring it, as a spin on the artist shredding his artwork as a "statement". A statement on a statement.

In an old newsletter I had some ways to duplicate signatures. The All Night Card and Further Adventures of the All Night Card. Good for a paying show, for your last trick of the night. I may go into more details in the Secret Sessions section near the bottom of the Café.

Back to the shredder. To change the card back from shredded to "restored", I'm thinking a change-bag of some kind. I'll bet Banksy wishes he thought of this!

I wonder if you could have an in-between stage where the card is semi restored - like, glued, but still fraying apart in a bunch of pieces. Jumbled, too, so the pieces weren't necessarily in order. Might be tricky with a signed card, but if you only flashed the semi-restored state, you might be able to get away with it.