The start was (I think) about 48° 2'7.98"N 0°25'3.27"E on the D323 between Connerre and Saint-Mars-la-Briere. That's were the first marker board is too.
It seems in the file I tidied it up a little and removed some of the double-backing we did. Here is a screenshot from Google Earth. Should be enough to get you there. It's more fun if you have to work something out yourself.
If you follow that then you do more about 99% of it. New junctions and that fact that some of the original course was actually temporary wooden boards means you can't quite do it all. Remember if you drive round it, but don't do the bit round Vibraye then you are a wuss
