Osmia Progress, full flex

Very nice and rare piston filler pen, Osmia Progress. Made in Germany in the late 1930’s/early 1940’s. DRGM stands for Deutsches Reichs-Gebrauchsmuster, which means the pen was surely not made after 1945. The color is unusal and so is the pattern seen on the ink window, the spiral stripes. The pen is equipped with a wonderful, smooth, very flexible original Osmia nib, F-1.8mm.