Possible inspiration for mending wall:
Henry David Thoreau, basically this loner guy, lived by himself, and wrote a book about it (or something like that) called "Walden" and the idea of a "bad neighbour" is when his cows cross over to your property. So good neighbour=no cows on your land = good fence to keep the cows away.
MOO
Another inspiration is the Roman holiday of Terminalia, to celebrate the god Terminus (the god of boundaries) (who knew?). Basically people would come and put food on their walls to honour the God, and then all the people would get together and have a great feast to celebrate boundaries.
Thought this might spark some conversation.