I tried that. It isn't working somehow. I put all the .scm files on /usr/share/festival, /mnt/us/arm-linux/share/festival, and also under /mnt/us/arm-linux/share/festival
I will check if I am doing something wrong at compiling time. If you want to have a look, let me know and I will upload what I've done so far. I don't mind credit, I want stuff that works. If you are interested in this, I can guide you on the modifications I've done to this. Or you can just run diff against the original source code.
P.S.: Is there an irc server/channel people around here hang out?