Good point actually. Hadn't thought about the potential powdercoat bubbling issue, thats probably it, they are def powdercoated black. Those stems must be steel as they didnt bend when I dropped the bike at 30mph, though they did scratch up good, hence my desire to change em out. My clutch lever pivot screw is stuck as well, its inches away and is most assuredly steel. Rust seems to be a very likely culprit to hit both places. That powdercoating really hides the telltale signs of rust.
Will get liquid wrench and try again. Hope it works on that pivot pin too, also have to change the lever out for the same reason.
Thank you both, and especially Mighty Gryphon for the anecdotal on this specific issue. I'll update on whether this works for future generations of motobrick owners.