In the 1841 Census it's Just classed as berkshire
In the 1851 and 1871 its classsed as Windsor
In the 1861 census its classed as Clewer.

I have found that Clewer and Windsor are sometimes used interchangeably due to being adjacent and while Clewer is still a town its classed as being in the parish of windsor.

I am certain all these are the right Thomas seymour for my family tree.