This version of  Onoto's  'The Pen' 6233 was first advertised in 1950, although it was probably available in the late 1940s.  The colour, described as 'Wine Pearl in the catalogue, is  a most attractive marbled pink, burgundy, and black with a pearlised finish.

The pen, a plunger filler. has been restored, including new seals, and tested, it is in excellent working condition.  It has a very good surface and clear barrel imprint.  The cap is a smooth screw fit, tightening with one and a quarter turns.

The Onoto nib is 14Ct. Gold, it writes with a very smooth line, perhaps a little on the fine side of medium. 

The somewhat 'quirky' but extremely efficient plunger filling system was first patented in 1905, it has certainly stood the test of time and helped establish  De La Rue and Onoto as a leading global brand.  Onoto plunger fillers are now much sought after and very collectable, high quality pens.