Having worked at Northampton last year I would say its not quite as simple as you suggest.
No changing rooms, no showers, no refs box,(but is a building that could be used) .
Foam fence is needed, but also wooden fencing to be made for the straights as that is steel plate aswell, plus some way of padding out the rope and post on top of the outer fence.
Earth mounds with steel plate would all need removing on the inside of the bends.
Then after all of that you need staff, licenced officials.
Don't get me wrong, I would love to see it happen.