Media Blasting Paint from 1970 Air Cleaner..........

[Too Many Projects]

With gray primer under the black, I doubt it's original paint. I've never seen anything but a thin coat of black on original parts under the hood and interior.
I'm with Gary and use crushed glass at LOW pressure ~ 40# and original paint disappears easily and the glass doesn't remove metal. It will leave a slight texture for the epoxy to bite into.