They are probably from a rental store, I have cut up boxes to Mario Party Advance and Final Fantasy 1&2 GBA from Block Buster. They stuck them in a DVD case to display them, I got them when I bought the rental copys a while back, they did came with their manuals. I think I acedentlay cut a small part of the FF back or front because the guy at the counter forgot to take the security thing out, and I was already home, and i decided to destroy the case to get the cart and manual out, this was in 2009.
Random tangent, I just woke up.