Sam,
Have you checked the Parish Records for Dilhorne? As I'm sure you already know, the submitted records on the IGI are not always correct. Your marriage has a specific date so is more likely to be correct than any entry giving approximations, however it is recommended that you check the PR's. You may also find more information about the family.
It is worthwhile checking trees that have been passed through the family. I know a distant ancestor of mine's research has connected to a wealthy family but looking closer at the tree, there is one vital missing link of no birth/baptismal record and no proof of parents for one particular person. Without that I can't add this wealthy family to my tree. However this tree is all over the internet and treated as gospel. Closer reading of the original researcher's notes back in the 1920's does mention this lack of proof, but people have just gone ahead and published nevertheless. So it pays to double check, especially when you get as far back as you have.