I don't really wish to get embroiled in this, but I don't think the use of extreme Nazi imaginary, sado masochism, child pornography and serial murderers et al. was back in the 70s & 80s of any help or support to those defending the liberties of free speech, gay and feminist rights etc. which were under attack by the likes of Mary Whitehouse & her "Moral Re-Armament".
As far as i'm aware child pornography will still get you into jail these days along with the newer hate crimes... looking at it this way using pictures of Nazi death chambers and associated insignia 31 years after the actual events didn't get those using them into jail, 44 years later a group using certain extreme religious tropes and reference to events of 911 would.
In 1968 GPO publishing instructions on how to build a Molotov cocktail.... didn't, would something similar now?
I'm cautions to say this but it could be that TG & Whitehouse's themes back then was more to shock an audience, rather than any genuine political critique. I don't think they, certainly not GPO was advocating Nazi extremism and paedophilia any more than Jake and Dinos Chapman using similar tropes, including child pornography, as YBAs in the 90s. The "irony" of the YBAs being perhaps more obvious. That some took this at all seriously?