I think Phil has a good idea. This would be RIGHT up Time Team's street, particularly as they are moving away from all that stone/bronze age stuff (I understand they're finding viewers are getting bored with flint arrow heads!).
They'll love the camera shots, and the wealth of programme material - and they'll excavate, restore and deal with the council for you. They carry a surprising amount of clout!
Superb site - the 'tunnels' section is fascinating!