I bought a copy of the game from ebay. Turned out the case was the wrong case (it was actually Dungeon Explorer). I convinced the guy to refund a small amount of the price, but now I need to find a real case. Does anyone have one for cheap (and/or that they'll trade for a Dungeon Explorer case)?
Perhaps the easiest solution would be to get one of Sparky's spine labels.
Sparky stickers are definitely the best cost effective solution. Not to mention they are very high quality. :)
https://www.pcengine-fx.com/forums/index.php?topic=5150.0