So, I wanted to do I Put A Spell On You for the Legion, having killed Vulpes there was no way to get the quest from him but the wiki states you should be able to get the quest from Hsu and then talk to Curtis.

So that's what I did, but had no joy getting Curtis to reveal he was working with the Legion (having an intelligence of 8 and being liked by the Legion). Reading the walkthrough it makes it sound like you should have this option when you initially talk to Curtis, however looking at the quick walkthrough it states to confront him instead in the control tower. I tried this also, but still couldn't find an option that didn't lead to him trying to kill me.

Is there anything I can do now to do the quest for the Legion? I have no saves to revert to before finding out from Boyd that someone's been breaking into the control tower, though I haven't mentioned this to Curtis yet.