Hey David,
I'm doing my best to trace it. Joseph is the furthest I've got back and he was born circa 1700. I know there is history of the Benn family in Haile and Egremont further back but haven't been able to confirm anything beyond Joseph yet. The oldest people I have available are Mum's first cousins and some other Benns that were not sure on the connection with yet. My Grandfather and his siblings have been gone a really long time now. I have one who has just sent away for the dna kit, I'm doing my best to convince everyone.
Lesa