Ive estimated its around 4,660 ft for the 100 miles. I did a 78 mile portion of the ride, but didnt do the climb up Wimbledon hill or Sawyers Hill and for my ride I got 4,543 via my Garmin. Theres a little discrepancy with the hills still to do, minus a little way I rode which wont be on the route, but its around that mark.
http://app.strava.com/activities/67112725
For what it's worth, I got a reading of nearly 6,000 ft of ascent without Leith Hill yesterday. That would be Ripley(ish) to Newlands Corner, A25 to Dorking, Box Hill, Headley Down, Leatherhead and up to Cobham before doubling back to Ripley. That was measured by Endomondo.
Mind you, it also said I hit 54 MPH at one point and I'm pretty sure I didn't. I think I might have noticed.