Hello Paul,
There is a chance that Joseph was alive at the time of Sarah's marriage, as I found this on FreeBMD.
Deaths Sept 1867 Reigate 2a 80
Vallance, Joseph Age 79
Reigate registration district includes Burstow.
It would put this Joseph's year of birth at about 1788, which would be about right on the assumption that Joseph was 21 when he married in 1809.
Phil