My son alerted me to a useful substance for stripping paint from metal figures. It is relatively cheap, safe to use, and present in many homes. Believe it or not, it is Dettol! I have experimented on both freshly (and badly) painted figures, and figures primed and underpainted several years ago. After a couple of hours immersed in a drop or two of Dettol, the paint comes off with the slightest touch of a brush. The only downside is that my painting room smells like a hospital!