These guys had 3-4 layers of oil paint (the Voltigeurs had been repainted over the original layer once, so count it 5-6) plus varnish. Five minutes in warm water (very warm, but not hot) spiced with Mr. Muscle drain cleaner granulate and they're good as new. I figured out it's faster if the container is sealed or covered so the fumes won't "get away" and do full effect on the paint. A really small work is needed to remove it from the more hideous spots.