yeah thats it, its the game genie codes. Ive never seen a box with an orange sky on the back, can you post a pic? Also send me a pm if you do end up parting with it.
*edit* i found a link of the back of the smb3 box that came with the challenge set
http://themushroomkingdom.net/ima...and there is no orange sky but i still never heard of an orange sky on the back of the box.