I'm not sure on the stub, it might have a different pcd for the driveshaft on a 2wd Cosworth. Apart from that the hub and hub carrier from the 2wd and 4x4 cosworth are the same. In fact these parts from the Scorpio 24v (bug eye) are also the same and probably much easier and cheaper to get.

If the stub is from a 4x4 Cosworth any Granada mk3 stub will fit. I wouldn't be worried about second hand items, I have never seen these break.