I used "Aircraft Remover" to take the paint off my Nelspot and that worked fine. Seriously, it's called "Aircraft Remover" ... it's made to take paint off of aluminum but generally works fine for other metals.
After that I just sanded and Scotch brite'd the outside. The inside of the barrel was worse though, and for that I used a shotgun hone, and then polished with a .30 cal cleaning kit using Scotch Brite ad a "patch" and some metal polish. Both the hone and the Scotch Brite were both run on a cordless drill.
If your glasses fog up and you want to make your own mask fans, here's how;
"My happiness doesn't depend on anything. My heart is always happy. I do have anger issues though."