Yes, L M ,
It must have been about 15 years ago I had a marriage that I was doubtful about, didn't feel like risking buying the cert. but I did know the church, St Giles Cripplegate whose records are at the Guildhall Library. Called in there & in a few moments had looked at the film & printed off a copy for the princely sum of 10p (well it was a long time ago), I think the GRO price at that time was about £5.50 or £6 per cert.
The cert. confirmed what info I had hoped for , that it was the marriage between my grgrandparents in 1879 aged 58 & 57, after having had 7 children between 1842 & 1858, including tripletes in 1848.. Grgrandpa finally made an "honest woman" of grandma.
Meliora