Hi,
That is bad luck,although,lots of people in that era had no grave-stone.I don't know how far back the church records go on burials,but it's worth asking.
I just had a thought,I wonder if any of them were burried a Allonby.That's only a couple of miles from Crosscanonby on the Solway Firth..
I love that area,I used to spend a lot of time up there.
Anyhow,best of luck and please letme know how you get on.