Excellent, I'll be looking forward to that chapter.
It's interesting to look at the difference in tone between letters featured in the Tower during Russell's time, and the tone of correspondence presented in the Rutherford era. The Bible Students seemed to have a strong element of "nice middle-class people," whereas the tone of the letters under Rutherford takes on a much more pugnacious, working-class quality. Certainly some of this has to do with the elimination of "character development" under Rutherford, but I suspect that Rutherford's ascendency in general pushed out nearly all these "nice middle class people" in favor of the rough-and-ready working-class folk who dominated the movement by the time of Stroup's study.
There's an excellent picture article in Life magazine around the time of the 1940 Detroit convention where you get a good clear look at the people in the crowd - and many look to be people who very obviously work in tough, blue-collar jobs, and who have the accompanying tough blue-collar attitude. I think that's the kind of people Rutherford wanted in his movement -- he didn't think much of the refined Olin Moyle type, who he dismissed as "sissies." And in the 1930s, most -- not all certainly, but if the 1936 and 1940 elections were any indication, most Americans in that social class -- tended to lean leftward politically.