Is he the William Marshall married to Maria?
The 1841 census doesn't tell you where someone was born - only whether born in county or not.
There is a William Marshall, living in Walsall, Staffordshire, who was born in county. Reference HO107, Piece 983, Book/Folio 14/37, Page 30.
Children Edwin, William, and Emelia.
The family can be found again in Walsall in 1861.
Reference RG09, 2106, 9, 13.
William with wife Maria and son William. All born in Walsall.
The 1851 census doesn't show a county, but appears to Stratford on ?? as William (senior) birthplace.
Reference HO107, 2023, 334, 23
I wonder if it should be Shelford, which was a hamlet in the parish of Walsall Foreign?