Hi Maddy,
On the marriage certificate,
Did Basil have any middle name listed, and what was his occupation, address and age?
Did his father have any occupation listed?
Are the witness' known to you - if not can you search for them, for any possible connection (can't list them here though in case still living).
Also, could I ask when was the last known 'sighting' of your grandfather?
I also wondered, how you know he was born in 1936?
Cheers,
Ambly