Dear Lin Thank you for your response. I think I will take your advice about applying to the GRO.
I think I found the marriage you suggested on Find My Past this says the spouse was Mary Jane Boon.But it is possible that there was a mistake.It may take time but I think the GRO index is my best bet. They check one year either side. And as you say no charge unless the names match.These were my 2X great grandparents,so it would be good if I could find this. Again many thanks I will post again if I have any luck, but it could take time.
Lesley