This would appear to be a standard jade green (turned to spinach color) flat top Parker Duofold, but the label says it is something else. It reads "Jade Lucky Curve George S Parker, (with the 'Parker' in an exaggerated script) Janesville. Second line 'Fountain Pen Tardemark Wisconsin, Third line: Reg U. S. Pat. Off." So what does that mean? Prior to 1926 Duofolds were made in black and red of hard rubber. In the summer of that year, the company exper...imented with Dupont plastic material and introduced the first plastic pens in the material called permanite. The color was jade green and although the models were identical with Duofolds, they were not introduced as a part of this series and were not engraved as such. They were known as Jade Pens, and were available in all three sizes with matching pencils. In mid-1927 the barrel imprint of the jade green models was altered to contain the Duofold trademark and thus became part ot the series (Lambrou - Fountain Pens of the World). This is that model in the senior oversized pen 5 1/2" long. You can see the usual spinach discoloration on the barrel, oxidation on the cap and tassie, and brassing of the cap band and the clip. The nib on this pen is marked Lucky Curve and is quite large. The size of the nib on these pens is always guess work, as unlike today they did not label them. This one probably leans towards a medium. THIS PEN DOES NOT DRAW INK. I am disposing the balance of my Parker Duofold collection in the next few days. Own a rare piece of Parker history - even if it is ugly! Check out my other auctions for some interesting pens.