I agree with Pat. You may want to use a stripper. The paint on the classic is either epoxy or urethane. Both should respond to stripper reasonably well. Most likely the paint was not baked on. Many of today's planes that are painted in the mold are very hard to strip down to the glass with stripper because of the baking. And they are also hard to sand.

I would use wet or dry wet paper to keep loading to a minimum on the fuse.