No way to make a SL-8 full auto legal. Don't even go there!
The way that the law was written would prohibit its manufacture. Registered sear or not.
I'd try to explain it, but it would be all wrong anyway. One of the techno-weenies can do it. No sense in typing and having it all chopped up.
I'm just saving you from the mental masturbation thing when you go to bed tonight.