I will email you directly with details of a family history website dedicated to the Jayne's and their relatives.
You will need to email the Administrator for access though as she appears to be a first cousin twice removed of your grandfather I doubt that will be a problem.

The Jayne's in my family tree to whom I am related are mainly 5th and 6th cousins. Given the links between Forest families, I suspect many users of this wonderful site are similarly related!

-Colin