Removing paint from factory locomotive shells

I am planning on re-painting a few locomotives shells over the winter. However, I have forgotten what to use to remove the orginal paint. I have some rubbing alcohol, I thought you could use a rubbing alcohol solution. Is that correct? If not, what do I need to get to be able to do this?

Thanks.

Which do you have? I use 97% Isoprpyl Alcohol for stripping factory shells (it won’t work on enamel paints though) and simply soak them in a rubbermaid container overnight, then use a toothbrush to work it the rest of the way off. I think I’ve seen 85% work also, though more slowly than the 97%

I have found 70% Isopropyl around the house. Will that work, or do I need a higher concentration?