My list would include:
Michael Parkinson - are his roots entirely in Yorkshire?
Jasper Carrot - of course, under his real name!
Mike Harding - the Crumpsall kid - but what if his ancestors came from over the pennines (with Parky's lot) ?
....and how about Stella Rimmington - be a laugh if they found a connection with Mata Hari (spies....!)