Actually, Nintendo introduced "Virtual Console" on the Wii system to make money off of these old games you can't buy anymore.
Downtown Special: Kunio-kun no Jidaigeki Dayo Zenin Shuugou! http://www.romhacking.net/translations/226/
Romancing SaGa 3 http://www.romhacking.net/translations/416/
Seiken Densetsu 3 http://www.romhacking.net/translations/440/
(Note: None of those links will point you at the ROMs themselves, just translation patches.)
There are toolkits out there that will let you peel them apart and see / replace the resources inside. I used this to swap out one ROM for another so I could play the Nintendo NES version of Tetris on my Wii.