In the 1891census, Samuel Vanstone age 4 was born in St David, Exeter, Devon. His parents were Christopher, age 40, and Mary A Vanstone, age 28. Christopher Vanstone was born in Sandford Courtney, Devon, in about 1851.
In the 1861 census, there's a Christopher Vanstone, born in Sampford Courteney, Devon, in about 1847, the son of John Vanstone and Jane Vanstone.
John Vanstone was born in Sampford Courteney in about 1801.
The same information is given in the 1851 census.