Rich - when I was away at college - DVOA had a few marathon/half marathon white courses. Pretty amazing.
It is interesting to see that it looks like Wyatt took the shortest route. I had it marked at 13.25 on Condes on me guessing the best route. I am seeing an extra mile or 2 on no mistake routes on the bike. You even won a split (straight uphill #20)!
We need to revive the O-marathon (well, the half was enough for me)