That's funny you mention this. That's actually how myself + spikeman did some romhacking, we reverse engineered a game genie code. I give spikeman all the credit, he's f#cking brilliant at this stuff.
To make this street fighter 2 romhack what I did was I first decoded the 1992 arcade hack roms by re-interleaving the data. I discovered that the hack was a hack of the retail version. Using the work they had done and the new code they added helped speed this up a lot.