I know you've been searching for this for ages, as have I a bit, and I just came across this which might help.
http://webcache.googleusercontent.com/search?q=cache:8fZVgum1E8sJ:www.ebooksread.com/authors-eng/jabez-allies/the-british-roman-and-saxon-antiquities-and-folklore-of-worcestershire-ala/page-13-the-british-roman-and-saxon-antiquities-and-folklore-of-worcestershire-ala.shtml+%22bolt+stone%22+kinver&cd=4&hl=en&ct=clnk&gl=uk

Looks like there may be two, and the myths became entangled.