I don't have nut files, I could probably do that if I did, maybe I should order some and cement the fact that I will have to build several more guitars

I don't see that I can slope the nut because it won't sit in the slot, so I don't think that's really an option. I already have the nut out from filing it down earlier, so that part is fine, it's just fixing this angle that's the problem. If I have to buy a new nut I need nut files anyway, so if anyone has any other DIY suggestions I'm all ears.