Thank you for this information, I had almost given up on finding this marriage.
I have John and Winny in the 1871 census, by 1881 they had moved to Wigan
Their children James 1870 and Thomas 1872 were born in Batley
John 1875 was born in Barnsley
Later children, including my grandmother Margaret Lavin 1875 were born in Wigan
Even though I now have the marriage date (with your help) in 1868, I still cannot see a marriage record in the usual BMD databases.
Perhaps they are hidden in another unusual variation of Lavin!!!
There are quite a few Lavins in the Wigan area, there is a Patrick Lavin, also marred to a Winifred, of a similar age to John Lavin, they have lived in the same streets in Wigan and I have always suspected that they were brothers, but cannot prove it.
Do you suspect that your Catherine Larvin and my Winifred Lavin have the same Patrick Lavin as theit father?
Did Catherine and John McManus stay in the Yorkshire area?