I considered that it could be a random rental but the sticker on it is really on there. Plus, what random rental place has a sticker that just happens to say "Prehistoric Man" and happens to be just about the right size to fit on the cart? Granted, the game itself is called "Prehistorik Man", but if it is a demo of sorts (pretty sure it's not a proto as the board has the correct product ID), they could have sent it out before they dropped the C and added the K.
Also, I don't know what's up with the stickers on the inside of the cart. I've opened several SNES games in the past and never seen one inside the case.