Good morning Jan,
I am not sure what you are trying to achieve with this post now.
You already had the information we have found with Mark being born in Saint Pancras.
The newspaper article refers to Mark as a native of Castor.
There is a death in 1838 for James Dewberry, 58 yrs, College Street which may be James, the father.
Also 1839 for Mary, 53 yrs, Little College Street.
We know that James Dewberry married Mary Hall as bachelor and spinster, in 1814.
Mark’s baptism shows mother as Sarah. It could be that ‘bachelor’ was an error in that 1814 record.
However, from census records, there are two Marks - one in St Pancras and one in Wood Walton.