If you can't locate a replacement hub there is a good chance that a good machine shop can repair your damaged hub. Most likely they would repair it by building up the bearing bore surface and then turning the surface back to the correct diameter on a lathe. I've seen hubs repaired this way before.
Air forums # 1674
1974 20' Argosy Motor Home
1974 31' Excella trailer (parting out, as of 4/1/2015 I have wheels, brake drums, windows & holding tanks left to sell)