Hi Scarrowman and welcome to our wee forum! I've added links to your post so that if anyone is interested they can read the story you mentioned (and others from the same book).
As for the inn, I assume its the one mentioned in the first paragraph:
Quote:
there stood far up the South Tyne, beyond Haltwhistle, on the road--then little better than a bridle-track--running over the Cumberland border by Brampton, an inn...
Looking at the map, the road mentioned probably followed the same route as the current A69; this road crosses from Northumberland in to Cumbria at Temon Bridge to the north of Denton Fell (shown on the 1:25,000 OS map at NY618638). Of course the inn could have been anywhere along that route, but hopefully this is a good starting point!
As for the authors, I'm afraid I don't know much about them, but I do believe they were related to Andrew; as Andrew lived from 1844-1912 and the above book was written c.1914, its more likely that John was his son rather than brother. So chances are John collected stories from various sources like Andrew did... tho there's also the possibility some were already known by Andrew and/or John!