Onoto 'The Pen' is more of a brand name than a model, there were scores of 'The Pens' msed over many years.  This pen is a model 640, made around 1937.

Consructed in celluloid with an engine turned chasing and nickel plated clip, the pen is in excellent condition although there is a smaal abrasion on the section as shown in th photograph. 

The plunger filling system has been overhauled, it is easy to use and takes up a 'barrel full' of ink in one operation of the plunger.  The nib, 14Ct. gold, has a medium point and a good amount of flex to add character to the writing.

The box has a few scuffs but is in fair condition and almost certainly original so should be kept with the pen.

Onoto Pens are extremely high quality and have become very collecable, the somewhat quirky but super efficent filling syatem adding to the appeal.