The true defining line between Left and Right is very hard to figure out, since many on both extremes sound very similar even as they hate each other. I have theorized in the past that the line is universalism vs. henotheism, or equality vs. hierarchy, or atomistic vs. "organic" collectivism, or horizontal vs. vertical collectivism. I've long since given up.
Please don't be offended by my position. I used to belong to the Birch Society, and I find much of their message to be hogwash.
As for putative rightists selling books by National Socialists, I would say this: it was only after Hitler that racialism was expelled from the left, and racialism was only expelled from the left because the Nazis had tried to take down Stalin.
Before the end of the Soviet-Nazi alliance, socialists had no problem being openly racialist: Jack London, Margaret Sanger, etc. Even black socialists like Marcus Garvey and W.E.B. DuBois had their own views on proper "racial hygiene" - few people today realize exactly what Garvey meant by naming his organization the "United Negro Improvement Association."
My definition for the left and the right is simply this: materialism vs. trust in the Almighty.