I can't exactly confirm this as I've only bought Famicom/Super Famicom games that were Japan only but supposedly if you insert a Japanese game that has an English version, it will dump the English version instead of the Japanese version. But yeah, who would create an English patch for a game that has a localized version already? I mean, unless the original translated script was really butchered or something.
Games are also translated through IPS patches. If you have an SD card, you place them on there and when you insert the game, you can apply the translation patch in the game's settings.
Oh, and in the end I decided it wasn't worth the gas to drive over to my stores so if MD/DC has any, it's all yours. I could have called, but I have no free time this weekend.