If you don't have the source code anymore, you could actually just download a RM decrypter from google to gain access to the files again. A whole bunch show up if you just google "Rpg Maker Decrypter." Part of what makes making rpg maker games scary is how easy they are to hack into, even with the encryption.
I'm really liking the colors on the thumbnail image for this. Might end up giving it a go, looks pretty slick.