Just a quick note to say thank you for the excellent guide for this route.
The GPX proved useful as well. Although there is a new path at SK 0675 6922 toward Harpur Hill that your GPX doesn't follow that caused a little confusion. But then it's only evident on Sustrans's maps. The OS still show the old route, as does Google.
Anyway, it was harder than I thought but a great adventure.
I'll post a link to the account when I've sorted the story out.