Hiya Kevin,
Ray Steton wrote a book called The Reason for the Stone Circles in Cumbria which was published in 1995. It's a nice little book I'm sure you'd like it. He too is a dowser. He surveyed 22 circles in Cumbria using conventional methods and then dowsed them. He didn't find straight lines but found serpentine lines running in and out of a number of the circles.
I guess even you dowsers have different ways of interpretting what you find.
cheers
fitz