That's going to be hard to find. And even if you do find one from a cyclone or v-series derailleur that looks similar, it may not be a perfect fit. Your best bet is to find a cheap donor derailleur.
It doesn't have to be perfect. But it does have to be real close to perfect. For example, if it isn't quite long enough, and the derailleur locks (doesn't swing freely) when the bolt is tightened, you might be able to use blue loctite to keep the bolt in place even with it not secured all the way down. I have done this with success with a Sprint derailleur.