James Aikman and Isabella Stein

I am searching for information on the ancestors of James Aikman and Isabella Stein, married in Barony, Lanark, Scotland on 19 March 1854. James was born in July 1821, in Lanarkshire, and Isabella was born on 10 Sept in Fifeshire. They immigrated to Australia in July 1854 aboard the 'Cairngorm' and lived in Mortlake, Victoria. Their daughter, Elizabeth was my great grandmother.
I have no information on their parents or siblings and would be delighted to hear from anyone who can shed any light on this!!