I am not sure if I posted this earlier, and Stark threads have gone into distant pages somewhere, so I thought I would post this.
I sent Dr. Stark an email requesting information as to which of his publications discusses the JWs. I also asked him if he was aware of Penton and Franz's work. He replied that he knew Penton and thought his work was of good quality.
He also stated, that he only wrote about the JWs in one article. It is in the Journal of Contempory Religion, 1997, Vol.12, pp 133-157. I am going to the library in a little while to see if I can find it.