So I've wheeled this all the way down on the exterior and just gave it a solid scraper on the interior (not planning on going any further inside).That is what I use to strip mine unless I take them to a sandblaster to have them do it. The angle grinder and wire wheel should work well.
Question on the exterior. Will I need to buff the wire wheel marks out with some fine grit sandpaper or will the paint be sufficient to cover these up? It's hard to tell on the bare metal if they are deep, but they feel smooth.
If further sanding for the finished product to look smooth and not swirly, what grit sandpaper do you suggest?
Also posted some update photos of the sides after 2 coats of high heat. I didn't have to sand those all the way down since I was able to clean them up with very minimal coating dmg.