This is the one I was thinking of: http://heathennoise.com/catalog/images/rac%20flag.jpg - looks fairly different though I suppose.
I can't confirm or deny it's been used in that context, I doubt most people on here will take it as anti-communist though.
Isn't your hammer & sickle skull pic an anti-communist symbol? I've seen Nazis wearing skulls biting the H&S on t-shirts and stuff.