Dang!
cardboardconnection says that some sketches combine with others to form a larger image.
Had a look at eBay, I noticed the GSP sketch card on there being sold by Brad Utterstrom himself, as one of the 6 artist returns he was allowed to keep. Its essentially the original sketch. While he says this makes it a true 1/1, wouldn't that mean 2 GSPs would end up in circulation?