Thanks Andrea for confirming.
If the marriage cert does confirm that John's dad is Simon Brian , then the 1881 census finding you have looks good.
I quite like the look of it, as the Mum of the John there is called Grace, and your John calls his daughter Grace. But that is not proof! You will need the cert.
If that turns out to be the right family then they are at
Rg10 4242 131 13 in 1871, but I wont post the details yet until we are sure this is the right line.
John pob varies from 1891 (Milnthorpe), the possible 1881 (Meeclop?) and possible 1871 (Bentham) so it is not all conclusive without the marriage cert.