Well put TG. Therein lies the beauty of the 24 Hr TT in my eyes, the fact that someone like me, who can put in a half decent 600, can enter it without fear of embarrassment.
Have a look at last year's Mersey Roads results. Quite a few AUK members in there, some doing (as TG says) 200 miles less than JW, but there to be counted none the less.
And back to the OP. The guy does not have an N+1, he has a bike that he's obviously honed to perfection (for him) through years of experience. Chapeau to him for an outstanding achievement, I'd like to meet him one day.