If you can't find a ref no and you could narrow it down to 3 years then you can still order a marriage certificate. I have had to do this for my g-g-grandparents. I knew both their names and where they were born and guessed they married just before their first child in 1851 so put the years 1849, 1850 and 1851. I had no idea where they married so have at least that. Anyway I got my cert within 2 weeks which isn't bad and I don't live in the uk.
It cost £11 but I think it is worth paying the bit extra to save yourself the stress and hardship
All the best Angela.
