FF1 for MSX is definitely real though, but one of the reasons you may not have heard of it is that it's not obvious how to actually get the game started, leading people (or at least me) to believe that the ROM was bad or fake. First of all, having the game disk isn't enough. You also need the user disk to save. Most importantly though, if you just start the game up without knowing what to do you get an error message. Not just any error message, a cryptic error message in Japanese that, depending on what kind of MSX you're running it on, may show up as gibberish. Even though I was able read the important part, I didn't put it together on my own. I eventually found the answer after searching Usenet archives. You have to hold the Control key (left Control Key in most emulators) while it's loading. It has to do with the game only wanting there to be one disk drive, which apparently frees up some RAM.
The MSX version of FF1 came out after the Famicom version, but before the NES release, so the graphics are still unedited. (In other words, the Clinic is a Church, the Eye is a Beholder, Medusa is topless, and the Master/Super Monk has wild, unkempt hair.) Although the graphics are not edited for content, they do have more colors to add depth and shading. The best way I can describe it is that it's like FF1 would look on the SMS. Also, the MSX isn't so good at smooth scrolling so when you walk around it's really jerky. The sound (in most cases) and music are better than the NES, but they switched a couple of songs for some reason.