TD - Thats just not right. 
Warm bed or cold North Sea and you chose the latter? Frozen testicles is all I've got to say to that one..... 
Hilly - Maybe a pair of spikes with 'L' and 'R' on the toes may help?
It will be interesting to see the results then after a few more months as it sounds like you may have just stepped over the overtraining line a wee bit, which is inevitable from time to time. I'm doing the same, in terms of concentrating on 5K for the next 11 weeks with the aim of clocking a 16:xx, so as to take more speed into the next marathon build up. Its worked before so we will see....
BR - It was 1993 not 1903!
But you're right - even in just 10 years it was a whole new ball game once the internet allowed sharing of ideas. Even though I trained now and again with a couple of 2:12 ish guys (who can say that now?) they kept their cards close to their chest in terms of their exact training.
You're right about Mr Horwill's input being invaluable - one thing about his approach, which is very much echoed by Charlie Spedding, is that you should train for a marathon just like any other race, ie to race it! None of this 'just getting round stuff'. In a way I'm really jealous of whats available now because the learning curve has been vastly shortened and that is part of the puzzle of why there arent more faster marathoners around.