Well I work in the automotive industry.
And I have to deal with stripping a lot of plastics.
I guess it depends on what the shell is made out of.
Chemically, most chemicals that will strip paint will effect most molded plastics. (Let me stress the word "Most")
Mechanical stripping with abrasives is generally considered the safest method.
But it can also get you into trouble. Too low of a grit, you get deep cuts which are hard to remove. start too fine of a grit and you end up clogging your paper up.
Maybe start with 220, then finish with 350.
The shell's are a little thin and too much sanding will thin it out more. so I'd do more of a leveling out of what is there then a full blow paint removal.
But The brake fluid is also worth trying.
I've seen it strip a lot of coatings. Lacquers, Urethanes, Epoxies.
It's not a fantastic stripper. it is rather slow. It is just Brake fluid after all.
But as far as a mild stripper for plastic. It's probably your best bet.
Just remember to clean your surface thoroughly with a Hand Dish soap like dawn, then wipe on wipe off with Rubbing alcohol to remove the oil or you won't get anything to stick to it.