Great, thanks for the patch, Alcahest. Everything seems to work fine. Granted, I haven't gotten that far yet, but so far so good. The original patch seems to work fine too with the clean version of the rom, but to avoid any possible bugs, it's of course better to use the overdump version as it was stated here before.
And I wouldn't worry about the whole "legal" thing. At this point, it's more of a so called "moral" issue rather than a "legal" issue since games older than ten years which are off the market tend to fall into the category of abandonware. It's not like Banpresto or any other company is going to track down everyone and sue them for playing a game made in the 90s which was never even released officially in English. Otherwise, all those tons of easy to find rom sites wouldn't even exist anymore. At this point, it's more about digital preservation rather than piracy and companies know this. This is especially true for games now over twenty years old such as NES and SNES ones. People download movies and songs all the time off the internet without getting into trouble and that's a much hotter issue than roms. So as long as you don't go crazy overboard with newer releases, you should be fine. And I wouldn't consider playing a rom a legal nor moral crime like robbing a bank either...
Edit: I mean of course, not in any sort of legal trouble unless you try to sell patches or roms. Now, those types of people are the real pirates, not honest fans like us.