Sorry for the non-scientific description! Finn's exit hole has grown down and he has quite a large bit of heel and sole flapping about, I suppose about a quarter of his foot. I can't get hold of the farrier to ask for advice (neither can anyone else, I pinged a friend who has him out regularly to see if he was going to be over and she's been trying to track him down for nearly a week, so I hope he's okay), so should I:
a) trim it off
b) leave it
c) encourage it to drop off with a bit of in-hand walking on the road
Finn's sound on it and it doesn't seem to be bothering him at all, he came trotting over for his breakfast as normal.