I have established that John is the son of William Hocking also aboard the Bussorah Merchant. Marriage record(No 726423)for John Hocking and Frances Nettell (1 Jul 1848)on the Cornwall OPC database confirms this. Apparently William also had a son James, but to my knowledge it has not been confirmed whether the James aboard the Bussorah Merchant is the son of William or the son of Joseph. The descendants of neither Joseph nor William appear to have any details of James Hocking in Australia.
I appreciate your interest and your response Thank you Janette