Huncamunca, I am only dipping in and out here. Is the register digitised on ancestry as part of the London collection?
I can't see it there, Blackmogs: they have only digitised stuff at London Metropolitan Archives, I think. If it had been a pre-1837 marriage it might have been online in the non-conformist records, but it's later. I think the registrar would have had to attend to record the marriage, which is why I've suggested trying the register office. Not certain though, so have my fingers crossed for polly.