Pen #19 is a 1955 Montblanc 149 piston-filler. Modern Montblancs are made of precious resin, which is indeed plastic. For those who are interested in the celluloid 149, this particular model is black celluloid with sterling silver outer cap bands. The clear celluloid windows tend to show wear and amber, but this window is still clean. The celluloid models have so much character that is hard for resin to capture!