My name is John Keay and I was just browsing and recognised the names James Keay and Janet Spy from a family tree my father has. I've just rung him and he says that Charles Keay (the father) was the son of James Keay and Margaret Macleish.
Their parent's were Peter Keay and Elsbeth Cadel. Peter's parents were John "Croft" Keay and Margaret Grigo and so on.
He reasonable sure he can trace it back to a William Keay (1550 - 1625) a brother (John)of which he this is the earliest relative we know of ourselves (probably).
My father is the genealogist of the family (not me) and may be able to give some more details.
If you would like me to get a copy of this branch of the tree please email me with your address and I will do so.