need original dff and txd files

[MaGGoT_7]

i need the original txd and dff files for the emporer as i replaced it with the doge viper and now my games crashing when i try to do a certain mission ( the first mision in san fiero where u have to use the emporer to pick up the 2 mechanics ) i can get to picking up the first mechanic but when u have to sound the horn the cut sceen starts and then the game just exits not sure if its coz of the doge but im guessing it is soo if some one could help me and give me the original files that would be a great help and would be highly apreciated thanx