Thanks so much for taking the time to reply Richard.
My details so far are slightly different to yours.
I have Thomas and Mary's marriage as 1847. (I'm waiting for the marriage cert.) The family also appears in the 1861 and 1871 census in Staffordshire. In 1879, the family left England for Australia aboard the "Lizzie Isedale".Eliz (18), Emily (14), Thomas (49), Mary (54), Sidney Thomas(11) (my great grandfather) and Thomas (20). Isaac and Martha came ahead with Martha's husband Charles Cork and their child George (1) on "The Caroline" on 12th October 1878.
On Thomas's death cert. his father is listed as Thomas, and his mother's surname as Airs. Mary (his wife) was also listed as Mary Riley. So that bit seems to be correct.
Charles Cork (son in law) registerd the death, so of course it's possible that he may have reported the wrong info.
I've so far come to a dead end with Thomas's parents...I'm hoping the marriage cert will confirm (or not) the details on his death cert. So many Thomas Brindleys out there. I'll let you know how I go.