Parker 51 Demonstrator. (1948) (8) Vac filler. Cap: Gold filled 1/10 12 kt. All original parts. Perfectly clear barrel with good imprints. Vac fill function excellent with new diaphragm.. Nib: gold, medium-broad. smooth. Measures: 5-7/16 capped. Condition: Extra Fine. Very Collectible. An excellent example of an early original demonstrator.