Ah, my bad. It's FCEUX, ver. 2.0. I think I'd tried soft-patching, at the start, but I might have skimmed over it with this emulator, so I'll try again. I'm using Quirino's translation, the one provided at the beginning of this thread. I don't know anything about ROM expansion, but from the searches I've done just now it looks like a rather involved process for NES ROMs in particular.
ETA: Okay, turns out I'm just really stupid. The original ROM I'd downloaded appeared to be Chinese (perhaps a pirated copy) and despite having taken a year's worth of Japanese, I didn't notice the difference... here I was wondering why there was so much kanji in the game. I've since downloaded a proper version and everything works perfectly. Thanks for the help, anyway. XD;