Some (Black Mask/Up Against the Wall Motherfucker) were explicitly anarchist. I am pretty sure it was in this time that Bookchin started to use the term, and while I am not into his brand of anarchism, I don't think I would exclude his work (at least at that point from falling in the big tent). In the UK there was King Mob. Probably lots of other stuff I don't know about.
Though he was explicitly not an anarchist, if you are interested in stuff from this era, I really liked the book For Worker's Power by Maurice Brinton, who was a libertarian socialist from the UK. The book spans a larger span of time than that, but even though I disagree with his perspective, I liked reading his stuff.