I have the map and list for this area. The plot occupied by William Dutton is actually a long narrow strip of land, one of three that are in a bigger field. It looks like it was divided for three people to farm. There is no building on it.
The nearest building is occupied by William Barrow, decribed as a house and garden .
The closest large building is occupied by William Lee, and is described as a House, garden and fold. I wonder if this is a clue to the name.
This is in the right area and the map actually has `to Bangor` on that road.
I know the area, I live about 7 miles away and my own family were living there in the 1800s . I`ve tried Old Maps UK, but even though the area is on the site as Isycoed, there are very few names of buildings, but my ancestral home Cornish Hall is. Once I found that I panned to the right and when you find the Nags head - that is where you are looking for.
Do you have other names, I still will try to find more for you.