I guess the OWs are stored in the ROM as uncompressed tiles. If you have some programming knowledge, it shouldn't be too hard to make a program to rip these and save them to image files. If you're interested, I can help you with that.
Alternatively, you could make a program to convert the sprite sheets into the correct format. I know Avatar posted RMXP character sets of all the FR/LG sprites. If you have RMXP already, you could try familiarizing yourself with RGSS's graphics functions. Again, if you need any help, just ask :)