Guys and Gals
I have done what was proposed as the route and it does not look at all a good route to keep people together, it would be a nightmare. (that is if I drove the right route). Anyway I have driven the A421 all the way to the A43 then up the A43 to the Silverstone turning, and on to gate 4. It took me 30 minutes and I used GSPies to register the route. So those with GPSies can download it from
http://www.gpsies.com/mapUser.do?username=la_vida_diver It will be obvious which one it is by it's title. It does go past the Layby that matters and I think it is fine.
Any problems I am at the hotel and can be reached in the usual manner as we have access to the wi-fi etc.