Karanest on Family Tree Circles

We have hit a brick wall with James! He is on the 1841 census of Northallerton, Yorkshire, as a Tailor.
He was living with - but not married to - Christiana MITCHELL. They had 4 children, born between 1835 and 1842.

James died on 10 January 1843. We are not certain of his birth date, as his age is taken from the 1841 census.

We cannot find his parents, as there is no birth certificate prior to 1837 and the surname is quite common!

Can anybody help, or suggest where we may look??