Hi Barbara,
Pre 1881 would be great. 1881 census shows only two children, John aged 9 (b c1871/2) and Ann aged 2 (b c1878/9), seems to be a big gap for the 1800's, however, if they married 1869 it would seem John was possibly the first born, unless there was one born soon after the marriage, perhaps shown on the 1871 census.
John Thompson (aka Johan) and Ann Vincent were my cousin's maternal grandparents, and we are trying to discover where the Danish root came in.
If he's there in 1871, hopefully it would show place of birth.
I had a look at the Middlesbrough index in the hope of picking up possible births of other Thompson children registered Guisborough, but there are so many of them it would be hard to say which - if any - belonged to John and Ann.
I've downloaded the form to send for a marriage certificate.
Many thanks
Margaret