This will be stating the obvious to those in the know, but I have just discovered how good acetone / nail varnish remover is at stripping paint off stuff and wanted to share it with anyone else who doesn't know.
I have a few items that have been customised in the past by their original owners. I tried it on a M3 grease gun which I painted as a kid, and a Germam officer cap which had been painted up and the paint cleaned off no bother. In fact the German cap lost its original Palitoy paint too. I applied the NVR to a cotton bud and gently rubbed, it took quite a few cotton buds as they did not work when clogged with paint.
It seems to me to be a gentler solvent than using cellulose thinners which was my first thought, and neither the plastic or rubber surfaces seem to have suffered any ill effects. I was concerned that cellulose thinners would damage the hard plastic of the gun.
I will be trying it next on my Land Rover which is sporting lovely blue wheels at the moment.