was pretty irrelevant and/or unknown.
The Holocaust became public knowledge around ’42/43 when the American govt published the first reports of mass murder in eastern Europe, and it was pretty common place to have German Jewish GI’s and Jewish neutralized German UK service men in regular units that had either fled Nazi Germany before the war, or had relatives there writing to them. And of course once the Allies reached mainland Europe it very quickly became obvious how the Nazis treated civilians, captured and injured soldiers and even their own. I think rather than unknown, certainly by mid war, most soldiers were aware of who they were fighting. Not least because as well as all the things above, they were being briefed through news-reels lectures and reading pamphlets about what was going on.
I think UK far right are attracted by post war revisionism and rehabilitation of some Nazis because of the cold war and the idea spread by some former Nazis that the plan ‘all along’ was to join forces to defeat Bolshevism (all a load of bollocks obvs) , and the usual other things that some folks are attracted to; the image, the weaponry, the ‘elitism’ and for some the idea that the Nazis were right all along – however unpalatable that seems.