I'm also related to William Nobes and Elizabeth Smith, who emigrated to Australia in 1853. I have a lot of information on their family, but am having a lot of trouble finding anything else earlier - I can't find the names of William Nobes' (b. 1820) parents.
If you want to see my research so far, you can view it online at http://family.stormshaker.com/genoprohttp://family.stormshaker.com/genopro. Scroll down the list of names on the left-hand side and you'll find William Nobes listed there (along with all the other William Nobeses!)