My grandmother was born Alice Mary Pole in 1876(?). We were always told we were descendants from the de la Poles! My grandmother was born in Bristol,from a banking family, and one of 9 children. Her father went bust and she came to Southern Africa to nurse, met my grandfather, John James Seton-Rogers, and had 4 children. Any links to either of the Pole families that you have found?
May be too modern! But worth a try- I have spent ages without much luck!