I've taken a very close look at the map, i.e. turned it inside out and upside down. 51% was what I ended up with. I don't change the marks anymore after I've given them, no matter the final rating. That way is most fair I think
I have to say that I agree with JV's review and score. 51% is over half marks and he has tried to give constructive help and advice that the mapper can learn from.