Hi Hilly, You could of course get away with the half, but there is also a good chance that it will still bein your legs 2 weeks later and that would be a pitty. As FAS says, if you feel you want to be at the event go and have a run around the other way and cheer people on - FLM is too big a target to mess up this time around and the half will always be there to do in the future.
Most of my generation did work of some kind - Charley Spedding ws a pharmasist and also worked for Nike for a while, Steve Jones was in the RAF, Eamon Martin worked for Ford. Hugh Jones was a full time student so I guess he was closest to being a pro runner. I think to bridge the gap between what we did - 2.08 & 09's to what they do now you would have to be full time with full time medical back up.
Longleat is available to enter on line on this site, I will have an entry form on my website in the next 24hrs. It is a figur 8 course starting and returning to the Marquis of Baths little house each time - pretty flat, with just a short rise on each loop, but no real hills....having done the risk assessment and planning of the course I think it is going to be a beautiful run.