Hi Peter
I have the surname of Kilgour appearing in my tree, way back - Mary Kilgour born 1809, daughter of James Kilgour born 1780, although both appear to have been born in Cramlington, Northumberland.
As for surnames being used as middle names, following on from the Kilgour line, the surname Patterson was given as a middle name, to various males in our family, until fairly recently.
justmej