Hmmm....
Don't know about where to buy a copy of that book, but I was looking for some of my ancestors from the WV (back then it was just VA - Pendleton area) and came across a site called hackerscreek.com
If you go to that site, on the left is a site menu, hit 'virtual library', then, when that page comes up, scroll down to the "Family Files" section and click on "Don Norman Files"....he has "Hefners" listed and quotes some of his info from that Kuhl book you mentioned.
The site mentions that he can be contacted thru that site, so that MIGHT be a way for you to get more info on that book or at least maybe get some copied pages of it....worth a try, eh?
Hope this helps some - good luck,
Kat